pygsti.circuits

A sub-package holding circuit-related objects

Subpackages

Submodules

Package Contents

Classes

Circuit

A quantum circuit.

CircuitList

A unmutable list (a tuple) of Circuit objects and associated metadata.

CircuitPlaquette

Encapsulates a single "plaquette" or "sub-matrix" within a circuit plot.

FiducialPairPlaquette

A plaquette whose rows and columns correspond to measurement and preparation fiducial circuits.

GermFiducialPairPlaquette

A plaquette whose rows and columns correspond to fiducial pairs and whose base is a germ-power.

PlaquetteGridCircuitStructure

Encapsulates a set of circuits, along with an associated structure.

Functions

create_circuits(*args, **kwargs)

Create a list of circuits using a nested loop.

repeat(x, num_times[, assert_at_least_one_rep])

Repeat x num_times times.

repeat_count_with_max_length(x, max_length[, ...])

The maximum number of times x can be repeated such that its length is <= max_length.

repeat_with_max_length(x, max_length[, ...])

Repeat the x an integer number of times such that the result has length <= max_length.

repeat_and_truncate(x, n[, assert_at_least_one_rep])

Repeat and truncate x to yield a sequence with exactly length n.

list_all_circuits(op_labels, minlength, maxlength)

List all the circuits in a given length range.

iter_all_circuits(op_labels, minlength, maxlength)

Iterative version of list_all_circuits()

list_all_circuits_onelen(op_labels, length)

List all the circuits of a given length.

iter_all_circuits_onelen(op_labels, length)

Iterative version of list_all_circuits_onelen()

list_all_circuits_without_powers_and_cycles(op_labels, ...)

List all distinct aperiodic circuits up to a maximum length.

list_random_circuits_onelen(op_labels, length, count)

Create a list of random circuits of a given length.

list_partial_circuits(circuit)

List the partial sub-circuits of circuit.

create_lgst_circuits(prep_fiducials, meas_fiducials, ...)

List the circuits required for running LGST.

list_circuits_lgst_can_estimate(dataset, ...)

Compute the circuits that LGST is able to estimate from dataset and sets of fiducials.

to_circuits(list_of_op_label_tuples_or_strings[, ...])

Converts a list of operation label tuples or strings to a list of Circuit objects.

translate_circuit(circuit, alias_dict)

Translates circuit according to the aliases in alias_dict.

translate_circuits(circuits, alias_dict)

Applies translate_circuit() to each element of circuits.

manipulate_circuit(circuit, rules[, line_labels])

Manipulates a Circuit object according to rules.

manipulate_circuits(circuits, rules[, line_labels])

Applies manipulate_circuit() to each element of circuits.

filter_circuits(circuits, sslbls_to_keep[, ...])

Applies filter_circuit() to each element of circuits.

filter_circuit(circuit, sslbls_to_keep[, new_sslbls, idle])

Filters circuit by keeping only a subset of its "lines" (i.e. state space labels, often qubits).

create_cloudnoise_circuits(processor_spec, ...[, ...])

Constructs a set of circuits that amplify all the parameters of a clould-noise model.

create_kcoverage_template(n, k[, verbosity])

Construct a template for how to create a "k-coverage" set of length-n sequences.

make_lsgst_structs(op_label_src, prep_strs, ...[, ...])

Deprecated function.

create_lsgst_circuit_lists(op_label_src, ...[, ...])

Create a set of long-sequence GST circuit lists (including structure).

create_lsgst_circuits(op_label_src, prep_strs, ...[, ...])

List all the circuits (i.e. experiments) required for long-sequence GST (LSGST).

create_elgst_lists(op_label_src, germ_list, ...[, ...])

Create a set of circuit lists for eLGST based on germs and max-lengths

create_elgst_experiment_list(op_label_src, germ_list, ...)

List of all the circuits (i.e. experiments) required for extended LGST (eLGST).

Attributes

RANK_TOL

class pygsti.circuits.Circuit(layer_labels=(), line_labels='auto', num_lines=None, editable=False, stringrep=None, name='', check=True, expand_subcircuits='default', occurrence=None, compilable_layer_indices=None)

Bases: object

A quantum circuit.

A Circuit represents a quantum circuit, consisting of state preparation, gates, and measurement operations. It is composed of some number of “lines”, typically one per qubit, and stores the operations on these lines as a sequence of Label objects, one per circuit layer, whose .sslbls members indicate which line(s) the label belongs on. When a circuit is created with ‘editable=True’, a rich set of operations may be used to construct the circuit in place, after which done_editing() should be called so that the Circuit can be properly hashed as needed.

Parameters

layer_labelsiterable of Labels or str

This argument provides a list of the layer labels specifying the state preparations, gates, and measurements for the circuit. This argument can also be a Circuit or a string, in which case it is parsed as a text-formatted circuit. Internally this will eventually be converted to a list of Label objects, one per layer, but it may be specified using anything that can be readily converted to a Label objects. For example, any of the following are allowed:

  • [‘Gx’,’Gx’] : X gate on each of 2 layers

  • [Label(‘Gx’),Label(‘Gx’)] : same as above

  • [(‘Gx’,0),(‘Gy’,0)] : X then Y on qubit 0 (2 layers)

  • [[(‘Gx’,0),(‘Gx’,1)],[(‘Gy’,0),(‘Gy’,1)]] : parallel X then Y on qubits 0 & 1

line_labelsiterable, optional

The (string valued) label for each circuit line. If ‘auto’, then line_labels is taken to be the list of all state-space labels present within layer_labels. If there are no such labels (e.g. if layer_labels contains just gate names like (‘Gx’,’Gy’)), then the special value ‘*’ is used as a single line label.

num_linesint, optional

Specify this instead of line_labels to set the latter to the integers between 0 and num_lines-1.

editablebool, optional

Whether the created Circuit is created in able to be modified. If True, then you should call done_editing() once the circuit is completely assembled, as this makes the circuit read-only and allows it to be hashed.

stringrepstring, optional

A string representation for the circuit. If None (the default), then this will be generated automatically when needed. One reason you’d want to specify this is if you know of a nice compact string representation that you’d rather use, e.g. “Gx^4” instead of the automatically generated “GxGxGxGx”. If you want to initialize a Circuit entirely from a string representation you can either specify the string in as layer_labels or set layer_labels to None and stringrep to any valid (one-line) circuit string.

namestr, optional

A name for this circuit (useful if/when used as a block within larger circuits).

checkbool, optional

Whether stringrep should be checked against layer_labels to ensure they are consistent, and whether the labels in layer_labels are a subset of line_labels. The only reason you’d want to set this to False is if you’re absolutely sure stringrep and line_labels are consistent and want to save computation time.

expand_subcircuitsbool or “default”

If “default”, then the value of Circuit.default_expand_subcircuits is used. If True, then any sub-circuits (e.g. anything exponentiated like “(GxGy)^4”) will be expanded when it is stored within the created Circuit. If False, then such sub-circuits will be left as-is. It’s typically more robust to expand sub-circuits as this facilitates comparison (e.g. so “GxGx” == “Gx^2”), but in cases when you have massive exponents (e.g. “Gx^8192”) it may improve performance to set expand_subcircuits=False.

occurrencehashable, optional

A value to set as the “occurrence id” for this circuit. This value doesn’t affect the circuit an any way except by affecting it’s hashing and equivalence testing. Circuits with different occurrence ids are not equivalent. Occurrence values effectively allow multiple copies of the same ciruit to be stored in a dictionary or DataSet.

compilable_layer_indicestuple, optional

The circuit-layer indices that may be internally altered (but retaining the same target operation) and/or combined with the following circuit layer by a hardware compiler.when executing this circuit. Layers that are not “compilable” are effectively followed by a barrier which prevents the hardward compiler from restructuring the circuit across the layer boundary.

Attributes

default_expand_subcircuitsbool

By default, expand sub-circuit labels.

line_labelstuple

The line labels (often qubit labels) of this circuit.

layertuptuple

This Circuit’s layers as a standard Python tuple of layer Labels.

tuptuple

This Circuit as a standard Python tuple of layer Labels and line labels.

strstr

The Python string representation of this Circuit.

Creates a new Circuit object, encapsulating a quantum circuit.

You only need to supply the first layer_labels argument, though usually (except for just 1 or 2 qubits) you’ll want to also supply line_labels or num_lines. If you’ll be adding to or altering the circuit before using it, you should set editable=True.

Parameters

layer_labelsiterable of Labels or str

This argument provides a list of the layer labels specifying the state preparations, gates, and measurements for the circuit. This argument can also be a Circuit or a string, in which case it is parsed as a text-formatted circuit. Internally this will eventually be converted to a list of Label objects, one per layer, but it may be specified using anything that can be readily converted to a Label objects. For example, any of the following are allowed:

  • [‘Gx’,’Gx’] : X gate on each of 2 layers

  • [Label(‘Gx’),Label(‘Gx’)] : same as above

  • [(‘Gx’,0),(‘Gy’,0)] : X then Y on qubit 0 (2 layers)

  • [[(‘Gx’,0),(‘Gx’,1)],[(‘Gy’,0),(‘Gy’,1)]] : parallel X then Y on qubits 0 & 1

line_labelsiterable, optional

The (string valued) label for each circuit line. If ‘auto’, then line_labels is taken to be the list of all state-space labels present within layer_labels. If there are no such labels (e.g. if layer_labels contains just gate names like (‘Gx’,’Gy’)), then the special value ‘*’ is used as a single line label.

num_linesint, optional

Specify this instead of line_labels to set the latter to the integers between 0 and num_lines-1.

editablebool, optional

Whether the created Circuit is created in able to be modified. If True, then you should call done_editing() once the circuit is completely assembled, as this makes the circuit read-only and allows it to be hashed.

stringrepstring, optional

A string representation for the circuit. If None (the default), then this will be generated automatically when needed. One reason you’d want to specify this is if you know of a nice compact string representation that you’d rather use, e.g. “Gx^4” instead of the automatically generated “GxGxGxGx”. If you want to initialize a Circuit entirely from a string representation you can either specify the string in as layer_labels or set layer_labels to None and stringrep to any valid (one-line) circuit string.

namestr, optional

A name for this circuit (useful if/when used as a block within larger circuits).

checkbool, optional

Whether stringrep should be checked against layer_labels to ensure they are consistent, and whether the labels in layer_labels are a subset of line_labels. The only reason you’d want to set this to False is if you’re absolutely sure stringrep and line_labels are consistent and want to save computation time.

expand_subcircuitsbool or “default”

If “default”, then the value of Circuit.default_expand_subcircuits is used. If True, then any sub-circuits (e.g. anything exponentiated like “(GxGy)^4”) will be expanded when it is stored within the created Circuit. If False, then such sub-circuits will be left as-is. It’s typically more robust to expand sub-circuits as this facilitates comparison (e.g. so “GxGx” == “Gx^2”), but in cases when you have massive exponents (e.g. “Gx^8192”) it may improve performance to set expand_subcircuits=False.

occurrencehashable, optional

A value to set as the “occurrence id” for this circuit. This value doesn’t affect the circuit an any way except by affecting it’s hashing and equivalence testing. Circuits with different occurrence ids are not equivalent. Occurrence values effectively allow multiple copies of the same ciruit to be stored in a dictionary or DataSet.

compilable_layer_indicestuple, optional

The circuit-layer indices that may be internally altered (but retaining the same target operation) and/or combined with the following circuit layer by a hardware compiler.when executing this circuit. Layers that are not “compilable” are effectively followed by a barrier which prevents the hardward compiler from restructuring the circuit across the layer boundary.

property line_labels

The line labels (often qubit labels) of this circuit.

property name

The name of this circuit.

Note: the name is not a part of the hashed value. The name is used to name the CircuitLabel returned from to_label().

property occurrence

The occurrence id of this circuit.

property layertup

This Circuit’s layers as a standard Python tuple of layer Labels.

Returns

tuple

property tup

This Circuit as a standard Python tuple of layer Labels and line labels.

Returns

tuple

property compilable_layer_indices

Tuple of the layer indices corresponding to “compilable” layers.

property compilable_by_layer

Boolean array indicating whether each layer is “compilable” or not.

property str

The Python string representation of this Circuit.

Returns

str

property layerstr

Just the string representation of the circuit layers (no ‘@<line_labels>’ suffix)

property linesstr

Just the string representation of the circuit’s line labels (the ‘@<line_labels>’ suffix)

property num_lines

The number of lines in this circuit.

Returns

int

property num_layers

The number of circuit layers.

In simple circuits, this is the same as the depth (given by depth()). For circuits containing sub-circuit blocks, this gives the number of top-level layers in this circuit.

Returns

int

property depth

The circuit depth.

This is the number of layers in simple circuits. For circuits containing sub-circuit blocks, this includes the full depth of these blocks. If you just want the number of top-level layers, use num_layers().

Returns

int

property width

The circuit width.

This is the number of qubits on which the circuit acts. This includes qubits that only idle, but are included as part of the circuit according to self.line_labels.

Returns

int

property size

Returns the circuit size.

This is the sum of the sizes of all the gates in the circuit. A gate that acts on n-qubits has a size of n, with the exception of the idle which has a size of 0. Hence, the circuit is given by: size = depth * num_lines - num_1Q_idles.

Returns

int

property duration
property num_gates

The number of gates in the circuit.

Returns

int

property num_multiq_gates

The number of multi-qubit (2+ qubits) gates in the circuit.

(Note that this cannot distinguish between “true” multi-qubit gates and gate that have been defined to act on more than one qubit but that represent some tensor-product gate.)

Returns

int

default_expand_subcircuits = 'True'
classmethod cast(obj)

Convert obj into a Circuit.

Parameters
objobject

Object to convert

Returns

Circuit

classmethod from_tuple(tup)

Creates a Circuit from a tuple

Parameters
tuptuple

The tuple to convert.

Returns

Circuit

to_label(nreps=1)

Construct and return this entire circuit as a CircuitLabel.

Note: occurrence-id information is not stored in a circuit label, so circuits that differ only in their occurence_id will return circuit labels that are equal.

Parameters
nrepsint, optional

The number of times this circuit will be repeated (CircuitLabels support exponentiation and you can specify this here).

Returns

CircuitLabel

repeat(ntimes, expand='default')

Repeat this circuit ntimes times.

Parameters
ntimesint

Number of repetitions.

expandbool or “default”, optional

When False, the returned circuit will contain a CircuitLabel encapsulating the repetitions without explicitly storing them. When True, the returned circuit will be expanded into the ntimes repetitions. “default” means to use the value in the class variable Circuit.default_expand_subcircuits.

copy(editable='auto')

Returns a copy of the circuit.

Parameters
editable{True,False,”auto”}

Whether returned copy is editable. If “auto” is given, then the copy is editable if and only if this Circuit is.

Returns

Circuit

clear()

Removes all the gates in a circuit (preserving the number of lines).

Returns

None

extract_labels(layers=None, lines=None, strict=True)

Get a subregion - a “rectangle” - of this Circuit.

This can be used to select multiple layers and/or lines of this Circuit. The strict argument controls whether gates need to be entirely within the given rectangle or can be intersecting it. If layers is a single integer then a Label is returned (representing a layer or a part of a layer), otherwise a Circuit is returned.

Parameters
layersint, slice, or list/tuple of ints

Which layers to select (the horizontal dimension of the selection rectangle). Layers are always selected by index, and this argument can be a single (integer) index - in which case a Label is returned - or multiple indices as given by a slice or list - in which case a Circuit is returned. Note that, even though we speak of a “rectangle”, layer indices do not need to be contiguous. The special value None selects all layers.

linesstr/int, slice, or list/tuple of strs/ints

Which lines to select (the vertical dimension of the selection rectangle). Lines are selected by their line-labels (elements of the circuit’s .line_labels property), which can be strings and/or integers. A single or multiple line-labels can be specified. If the line labels are integers a slice can be used, otherwise a list or tuple of labels is the only way to select multiple of them. Note that line-labels do not need to be contiguous. The special value None selects all lines.

strictbool, optional

When True, only gates lying completely within the selected region are included in the return value. If a gate straddles the region boundary (e.g. if we select just line 1 and the circuit contains “Gcnot:1:2”) then it is silently not-included in the returned label or circuit. If False, then gates which straddle the region boundary are included. Note that this may result in a Label or Circuit containing more line labels than where requested in the call to extract_labels(…)..

Returns
Label or Circuit

The requested portion of this circuit, given as a Label if layers is a single integer and as a Circuit otherwise. Note: if you want a Circuit when only selecting one layer, set layers to a slice or tuple containing just a single index.

set_labels(lbls, layers=None, lines=None)

Write lbls to the block defined by the layers and lines arguments.

Note that lbls can be anything interpretable as a Label or list of labels.

Parameters
lblsLabel, list/tuple of Labels, or Circuit

When layers is a single integer, lbls should be a single “layer label” of type Label. Otherwise, lbls should be a list or tuple of Label objects with length equal to the number of layers being set. A Circuit may also be used in this case.

layersint, slice, or list/tuple of ints

Which layers to set (the horizontal dimension of the destination rectangle). Layers are always selected by index, and this argument can be a single (integer) index or multiple indices as given by a slice or list. Note that these indices do not need to be contiguous. The special value None stands for all layers.

linesstr/int, slice, or list/tuple of strs/ints

Which lines to set (the vertical dimension of the destination rectangle). Lines are selected by their line-labels, which can be strings and/or integers. A single or multiple line-labels can be specified. If the line labels are integers a slice can be used, otherwise a list or tuple of labels is the only way to specify multiple of them. The line-labels do not need to be contiguous. The special value None stands for all lines, and in this case new lines will be created if there are new state-space labels in lbls (when lines is not None an error is raised instead).

Returns

None

insert_idling_layers(insert_before, num_to_insert, lines=None)

Inserts into this circuit one or more idling (blank) layers, returning a copy.

By default, complete layer(s) are inserted. The lines argument allows you to insert partial layers (on only a subset of the lines).

Parameters
insert_beforeint

The layer index to insert the new layers before. Can be from 0 (insert at the beginning) to len(self)-1 (insert at end), and negative indexing can be used to insert relative to the last layer. The special value None inserts at the end.

num_to_insertint

The number of new layers to insert.

linesstr/int, slice, or list/tuple of strs/ints, optional

Which lines should have new layers (blank circuit space) inserted into them. A single or multiple line-labels can be specified, similarly as in extract_labels(). The default value None stands for all lines.

Returns

Circuit

insert_idling_layers_inplace(insert_before, num_to_insert, lines=None)

Inserts into this circuit one or more idling (blank) layers.

By default, complete layer(s) are inserted. The lines argument allows you to insert partial layers (on only a subset of the lines).

Parameters
insert_beforeint

The layer index to insert the new layers before. Can be from 0 (insert at the beginning) to len(self)-1 (insert at end), and negative indexing can be used to insert relative to the last layer. The special value None inserts at the end.

num_to_insertint

The number of new layers to insert.

linesstr/int, slice, or list/tuple of strs/ints, optional

Which lines should have new layers (blank circuit space) inserted into them. A single or multiple line-labels can be specified, similarly as in extract_labels(). The default value None stands for all lines.

Returns

None

insert_labels_into_layers(lbls, layer_to_insert_before, lines=None)

Inserts into this circuit the contents of lbls into new full or partial layers, returning a copy.

By default, complete layer(s) are inserted. The lines argument allows you to insert partial layers (on only a subset of the lines).

Parameters
lblslist/tuple of Labels, or Circuit

The full or partial layer labels to insert. The length of this list, tuple, or circuit determines the number of layers which are inserted.

layer_to_insert_beforeint

The layer index to insert lbls before. Can be from 0 (insert at the beginning) to len(self)-1 (insert at end), and negative indexing can be used to insert relative to the last layer. The special value None inserts at the end.

linesstr/int, slice, or list/tuple of strs/ints, optional

Which lines should have lbls inserted into them. Currently this can only be a larger set than the set of line labels present in lbls (in future versions this may allow filtering of lbls). value None stands for all lines.

Returns

Circuit

insert_labels_into_layers_inplace(lbls, layer_to_insert_before, lines=None)

Inserts into this circuit the contents of lbls into new full or partial layers.

By default, complete layer(s) are inserted. The lines argument allows you to insert partial layers (on only a subset of the lines).

Parameters
lblslist/tuple of Labels, or Circuit

The full or partial layer labels to insert. The length of this list, tuple, or circuit determines the number of layers which are inserted.

layer_to_insert_beforeint

The layer index to insert lbls before. Can be from 0 (insert at the beginning) to len(self)-1 (insert at end), and negative indexing can be used to insert relative to the last layer. The special value None inserts at the end.

linesstr/int, slice, or list/tuple of strs/ints, optional

Which lines should have lbls inserted into them. Currently this can only be a larger set than the set of line labels present in lbls (in future versions this may allow filtering of lbls). value None stands for all lines.

Returns

None

insert_idling_lines(insert_before, line_labels)

Insert one or more idling (blank) lines into this circuit, returning a copy.

Parameters
insert_beforestr or int

The line label to insert new lines before. The special value None inserts lines at the bottom of this circuit.

line_labelslist or tuple

A list or tuple of the new line labels to insert (can be integers and/or strings).

Returns

Circuit

insert_idling_lines_inplace(insert_before, line_labels)

Insert one or more idling (blank) lines into this circuit.

Parameters
insert_beforestr or int

The line label to insert new lines before. The special value None inserts lines at the bottom of this circuit.

line_labelslist or tuple

A list or tuple of the new line labels to insert (can be integers and/or strings).

Returns

None

insert_labels_as_lines_inplace(lbls, layer_to_insert_before=None, line_to_insert_before=None, line_labels='auto')

Inserts into this circuit the contents of lbls into new lines.

By default, lbls is inserted at the beginning of the new lines(s). The layer_to_insert_before argument allows you to insert lbls beginning at a layer of your choice.

Parameters
lblslist/tuple of Labels, or Circuit

A list of layer labels to insert as new lines. The state-space (line) labels within lbls must not overlap with that of this circuit or an error is raised. If lbls contains more layers than this circuit currently has, new layers are added automatically.

layer_to_insert_beforeint

The layer index to insert lbls before. Can be from 0 (insert at the beginning) to len(self)-1 (insert at end), and negative indexing can be used to insert relative to the last layer. The default value of None inserts at the beginning.

line_to_insert_beforestr or int

The line label to insert the new lines before. The default value of None inserts lines at the bottom of the circuit.

line_labelslist, tuple, or “auto”

The labels of the new lines being inserted. If “auto”, then these are inferred from lbls.

Returns

None

insert_labels_as_lines(lbls, layer_to_insert_before=None, line_to_insert_before=None, line_labels='auto')

Inserts into this circuit the contents of lbls into new lines, returning a copy.

By default, lbls is inserted at the beginning of the new lines(s). The layer_to_insert_before argument allows you to insert lbls beginning at a layer of your choice.

Parameters
lblslist/tuple of Labels, or Circuit

A list of layer labels to insert as new lines. The state-space (line) labels within lbls must not overlap with that of this circuit or an error is raised. If lbls contains more layers than this circuit currently has, new layers are added automatically.

layer_to_insert_beforeint

The layer index to insert lbls before. Can be from 0 (insert at the beginning) to len(self)-1 (insert at end), and negative indexing can be used to insert relative to the last layer. The default value of None inserts at the beginning.

line_to_insert_beforestr or int

The line label to insert the new lines before. The default value of None inserts lines at the bottom of the circuit.

line_labelslist, tuple, or “auto”

The labels of the new lines being inserted. If “auto”, then these are inferred from lbls.

Returns

None

clear_labels(layers=None, lines=None, clear_straddlers=False)

Removes all the gates within the given circuit region. Does not reduce the number of layers or lines.

Parameters
layersint, slice, or list/tuple of ints

Defines the horizontal dimension of the region to clear. See extract_labels() for details.

linesstr/int, slice, or list/tuple of strs/ints

Defines the vertical dimension of the region to clear. See extract_labels() for details.

clear_straddlersbool, optional

Whether or not gates which straddle cleared and non-cleared lines should be cleared. If False and straddling gates exist, an error will be raised.

Returns

None

delete_layers(layers=None)

Deletes one or more layers from the circuit.

Parameters
layersint, slice, or list/tuple of ints

The layer index or indices to delete. See extract_labels() for details.

Returns

None

delete_lines(lines, delete_straddlers=False)

Deletes one or more lines from the circuit.

Parameters
linesstr/int, slice, or list/tuple of strs/ints

The line label(s) to delete. See extract_labels() for details.

delete_straddlersbool, optional

Whether or not gates which straddle deleted and non-deleted lines should be removed. If False and straddling gates exist, an error will be raised.

Returns

None

to_pythonstr(op_labels)

Convert this circuit to an “encoded” python string.

In the returned string each operation label is represented as a single character, starting with ‘A’ and continuing down the alphabet. This can be useful for processing operation sequences using python’s string tools (regex in particular).

Parameters
op_labelstuple

An iterable containing at least all the layer-Labels that appear in this Circuit, and which will be mapped to alphabet characters, beginning with ‘A’.

Returns
string

The converted operation sequence.

Examples

(‘Gx’,’Gx’,’Gy’,’Gx’) => “AABA”

classmethod from_pythonstr(python_string, op_labels)

Decode an “encoded string” into a Circuit.

Create a Circuit from a python string where each operation label is represented as a single character, starting with ‘A’ and continuing down the alphabet. This performs the inverse of to_pythonstr().

Parameters
python_stringstring

string whose individual characters correspond to the operation labels of a operation sequence.

op_labelstuple

tuple containing all the operation labels that will be mapped from alphabet characters, beginning with ‘A’.

Returns

Circuit

Examples

“AABA” => (‘Gx’,’Gx’,’Gy’,’Gx’)

serialize(expand_subcircuits=False)

Serialize the parallel gate operations of this Circuit.

Construct a new Circuit whereby all layers containing multiple gates are converted to separate single-gate layers, effectively putting each elementary gate operation into its own layer. Ordering is dictated by the ordering of the compound layer labels.

Parameters
expand_subcircuitsbool

Whether subcircuits should be expanded before performing the serialization. If False, the circuit may contain CircuitLabel layers.

Returns

Circuit

parallelize(can_break_labels=True, adjacent_only=False)

Compress a circuit’s gates by performing them in parallel.

Construct a circuit with the same underlying labels as this one, but with as many gates performed in parallel as possible (with some restrictions - see the Parameters section below). Generally, gates are moved as far left (toward the start) of the circuit as possible.

Parameters
can_break_labelsbool, optional

Whether compound (parallel-gate) labels in this Circuit can be separated during the parallelization process. For example, if can_break_labels=True then “Gx:0[Gy:0Gy:1]” => “[Gx:0Gy:1]Gy:0” whereas if can_break_labels=False the result would remain “Gx:0[Gy:0Gy:1]” because [Gy:0Gy:1] cannot be separated.

adjacent_onlybool, optional

It True, then operation labels are only allowed to move into an adjacent label, that is, they cannot move “through” other operation labels. For example, if adjacent_only=True then “Gx:0Gy:0Gy:1” => “Gx:0[Gy:0Gy:1]” whereas if adjacent_only=False the result would be “[Gx:0Gy:1]Gy:0. Setting this to True is sometimes useful if you want to parallelize a serial string in such a way that subsequently calling .serialize() will give you back the original string.

Returns

Circuit

expand_subcircuits_inplace()

Expands all CircuitLabel labels within this circuit.

This operation is done in place and so can only be performed on an editable Circuit.

Returns

None

expand_subcircuits()

Returns a new circuit with CircuitLabel labels expanded.

Returns

Circuit

factorize_repetitions_inplace()

Attempt to replace repeated sub-circuits with CircuitLabel objects.

More or less the reverse of expand_subcircuits(), this method attempts to collapse repetitions of the same labels into single CircuitLabel labels within this circuit.

This operation is done in place and so can only be performed on an editable Circuit.

Returns

None

insert_layer(circuit_layer, j)

Inserts a single layer into a circuit, returning a copy.

The input layer does not need to contain a gate that acts on every qubit, but it should not contain more than one gate on a qubit.

Parameters
circuit_layerLabel

The layer to insert. A (possibly compound) Label object or something that can be converted into one, e.g. ((‘Gx’,0),(‘Gcnot’,1,2)) or just ‘Gx’.

jint

The layer index (depth) at which to insert the circuit_layer.

Returns

Circuit

insert_layer_inplace(circuit_layer, j)

Inserts a single layer into a circuit.

The input layer does not need to contain a gate that acts on every qubit, but it should not contain more than one gate on a qubit.

Parameters
circuit_layerLabel

The layer to insert. A (possibly compound) Label object or something that can be converted into one, e.g. ((‘Gx’,0),(‘Gcnot’,1,2)) or just ‘Gx’.

jint

The layer index (depth) at which to insert the circuit_layer.

Returns

None

insert_circuit(circuit, j)

Inserts a circuit into this circuit, returning a copy.

The circuit to insert can be over more qubits than this circuit, as long as all qubits that are not part of this circuit are idling. In this case, the idling qubits are all discarded. The circuit to insert can also be on less qubits than this circuit: all other qubits are set to idling. So, the labels of the circuit to insert for all non-idling qubits must be a subset of the labels of this circuit.

Parameters
circuitCircuit

The circuit to be inserted.

jint

The layer index (depth) at which to insert the circuit.

Returns

Circuit

insert_circuit_inplace(circuit, j)

Inserts a circuit into this circuit.

The circuit to insert can be over more qubits than this circuit, as long as all qubits that are not part of this circuit are idling. In this case, the idling qubits are all discarded. The circuit to insert can also be on less qubits than this circuit: all other qubits are set to idling. So, the labels of the circuit to insert for all non-idling qubits must be a subset of the labels of this circuit.

Parameters
circuitCircuit

The circuit to be inserted.

jint

The layer index (depth) at which to insert the circuit.

Returns

None

append_circuit(circuit)

Append a circuit to the end of this circuit, returning a copy.

This circuit must satisfy the requirements of insert_circuit(). See that method for more details.

Parameters
circuitA Circuit object

The circuit to be appended.

Returns

Circuit

append_circuit_inplace(circuit)

Append a circuit to the end of this circuit.

This circuit must satisfy the requirements of insert_circuit(). See that method for more details.

Parameters
circuitA Circuit object

The circuit to be appended.

Returns

None

prefix_circuit(circuit)

Prefix a circuit to the beginning of this circuit, returning a copy.

This circuit must satisfy the requirements of the insert_circuit(). See that method for more details.

Parameters
circuitA Circuit object

The circuit to be prefixed.

Returns

Circuit

prefix_circuit_inplace(circuit)

Prefix a circuit to the beginning of this circuit.

This circuit must satisfy the requirements of the insert_circuit(). See that method for more details.

Parameters
circuitA Circuit object

The circuit to be prefixed.

Returns

None

tensor_circuit_inplace(circuit, line_order=None)

The tensor product of this circuit and circuit.

That is, it adds circuit to this circuit as new lines. The line labels of circuit must be disjoint from the line labels of this circuit, as otherwise applying the circuits in parallel does not make sense.

Parameters
circuitA Circuit object

The circuit to be tensored.

line_orderList, optional

A list of all the line labels specifying the order of the circuit in the updated circuit. If None, the lines of circuit are added below the lines of this circuit. Note that, for many purposes, the ordering of lines of the circuit is irrelevant.

Returns

None

tensor_circuit(circuit, line_order=None)

The tensor product of this circuit and circuit, returning a copy.

That is, it adds circuit to this circuit as new lines. The line labels of circuit must be disjoint from the line labels of this circuit, as otherwise applying the circuits in parallel does not make sense.

Parameters
circuitA Circuit object

The circuit to be tensored.

line_orderList, optional

A list of all the line labels specifying the order of the circuit in the updated circuit. If None, the lines of circuit are added below the lines of this circuit. Note that, for many purposes, the ordering of lines of the circuit is irrelevant.

Returns

Circuit

replace_layer_with_circuit_inplace(circuit, j)

Replaces the j-th layer of this circuit with circuit.

Parameters
circuitCircuit

The circuit to insert

jint

The layer index to replace.

Returns

None

replace_layer_with_circuit(circuit, j)

Replaces the j-th layer of this circuit with circuit, returning a copy.

Parameters
circuitCircuit

The circuit to insert

jint

The layer index to replace.

Returns

Circuit

replace_gatename_inplace(old_gatename, new_gatename)

Changes the name of a gate throughout this Circuit.

Note that the name is only a part of the label identifying each gate, and doesn’t include the lines (qubits) a gate acts upon. For example, the “Gx:0” and “Gx:1” labels both have the same name but act on different qubits.

Parameters
old_gatenamestr

The gate name to replace.

new_gatenamestr

The name to replace old_gatename with.

Returns

None

replace_gatename(old_gatename, new_gatename)

Returns a copy of this Circuit except that old_gatename is changed to new_gatename.

Note that the “name” is only a part of the “label” identifying each gate, and doesn’t include the lines (qubits) a gate acts upon. For example, the “Gx:0” and “Gx:1” labels both have the same name but act on different qubits.

Parameters
old_gatenamestr

The gate name to replace.

new_gatenamestr

The name to replace old_gatename with.

Returns

Circuit

replace_gatename_with_idle_inplace(gatename)

Treats a given gatename as an idle gate throughout this Circuit.

This effectively removes this gate name from the circuit, and replaces a layer containing only this gate name with an idle layer.

Parameters
gatenamestr

The gate name to replace.

Returns

None

replace_gatename_with_idle(gatename)

Returns a copy of this Circuit with a given gatename treated as an idle gate.

This effectively removes this gate name from the circuit, and replaces a layer containing only this gate name with an idle layer.

Parameters
gatenamestr

The gate name to replace.

Returns

Circuit

replace_layer(old_layer, new_layer)

Returns a copy of this Circuit except that old_layer is changed to new_layer.

Parameters
old_layerstr or Label

The layer to find.

new_layerstr or Label

The layer to replace found layers with.

Returns

Circuit

replace_layers_with_aliases(alias_dict)

Performs a find and replace using layer aliases.

Returns a copy of this Circuit except that it’s layers that match keys of alias_dict are replaced with the corresponding values.

Parameters
alias_dictdict

A dictionary whose keys are layer Labels (or equivalent tuples or strings), and whose values are Circuits.

Returns

Circuit

change_gate_library(compilation, allowed_filter=None, allow_unchanged_gates=False, depth_compression=True, one_q_gate_relations=None)

Re-express a circuit over a different model.

Parameters
compilationdict or CompilationLibrary.

If a dictionary, the keys are some or all of the gates that appear in the circuit, and the values are replacement circuits that are normally compilations for each of these gates (if they are not, the action of the circuit will be changed). The circuits need not be on all of the qubits, and need only satisfy the requirements of the insert_circuit method. There must be a key for every gate except the self.identity gate, unless allow_unchanged_gates is False. In that case, gate that aren’t a key in this dictionary are left unchanged.

If a CompilationLibrary, this will be queried via the retrieve_compilation_of() method to find compilations for all of the gates in the circuit. So this CompilationLibrary must contain or be able to auto-generate compilations for the requested gates, except when allow_unchanged_gates is True. In that case, gates that a compilation is not returned for are left unchanged.

allowed_filterdict or set, optional

Specifies which gates are allowed to be used when generating compilations from compilation. Can only be not None if compilation is a CompilationLibrary. If a dict, keys must be gate names (like “Gcnot”) and values QubitGraph objects indicating where that gate (if it’s present in the library) may be used. If a set, then it specifies a set of qubits and any gate in the current library that is confined within that set is allowed. If None, then all gates within the library are allowed.

allow_unchanged_gatesbool, optional

Whether to allow some gates to remain unchanged, and therefore to be absent from compilation. When True such gates are left alone; when False an error is raised if any such gates are encountered.

depth_compressionbool, optional

Whether to perform depth compression after changing the gate library. If one_q_gate_relations is None this will only remove idle layers and compress the circuit by moving everything as far forward as is possible without knowledge of the action of any gates other than self.identity. See the depth_compression method for more details. Under most circumstances this should be true; if it is False changing gate library will often result in a massive increase in circuit depth.

one_q_gate_relationsdict, optional

Gate relations for the one-qubit gates in the new gate library, that are used in the depth compression, to cancel / combine gates. E.g., one key-value pair might be (‘Gh’,’Gh’) : ‘I’, to signify that two Hadamards c ompose to the idle gate ‘Gi’. See the depth_compression() method for more details.

Returns

None

map_names_inplace(mapper)

The names of all of the simple labels are updated in-place according to the mapping function mapper.

Parameters
mapperdict or function

A dictionary whose keys are the existing gate name values and whose values are the new names (strings) or a function which takes a single (existing name) argument and returns a new name.

Returns

None

map_state_space_labels_inplace(mapper)

The labels of all of the lines (wires/qubits) are updated according to the mapping function mapper.

Parameters
mapperdict or function

A dictionary whose keys are the existing self.line_labels values and whose value are the new labels, or a function which takes a single (existing line-label) argument and returns a new line-label.

Returns

None

map_state_space_labels(mapper)

Creates a new Circuit whose line labels are updated according to the mapping function mapper.

Parameters
mapperdict or function

A dictionary whose keys are the existing self.line_labels values and whose value are the new labels, or a function which takes a single (existing line-label) argument and returns a new line-label.

Returns

Circuit

reorder_lines_inplace(order)

Reorders the lines (wires/qubits) of the circuit.

Note that the ordering of the lines is unimportant for most purposes.

Parameters
orderlist

A list containing all of the circuit line labels (self.line_labels) in the order that the should be converted to.

Returns

None

reorder_lines(order)

Reorders the lines (wires/qubits) of the circuit, returning a copy.

Note that the ordering of the lines is unimportant for most purposes.

Parameters
orderlist

A list containing all of the circuit line labels (self.line_labels) in the order that the should be converted to.

Returns

Circuit

idling_lines(idle_layer_labels=None)

Returns the line labels corresponding to idling lines.

Parameters
idle_layer_labelsiterable, optional

A list or tuple of layer-labels that should be treated as idle operations, so their presence will not disqualify a line from being “idle”. E.g. [“Gi”] will cause “Gi” layers to be considered idle layers.

Returns

tuple

delete_idling_lines_inplace(idle_layer_labels=None)

Removes from this circuit all lines that are idling at every layer.

Parameters
idle_layer_labelsiterable, optional

A list or tuple of layer-labels that should be treated as idle operations, so their presence will not disqualify a line from being “idle”. E.g. [“Gi”] will cause “Gi” layers to be considered idle layers.

Returns

None

delete_idling_lines(idle_layer_labels=None)

Removes from this circuit all lines that are idling at every layer, returning a copy.

Parameters
idle_layer_labelsiterable, optional

A list or tuple of layer-labels that should be treated as idle operations, so their presence will not disqualify a line from being “idle”. E.g. [“Gi”] will cause “Gi” layers to be considered idle layers.

Returns

Circuit

replace_with_idling_line_inplace(line_label, clear_straddlers=True)

Converts the specified line to an idling line, by removing all its gates.

If there are any multi-qubit gates acting on this line, this function will raise an error when clear_straddlers=False.

Parameters
line_labelstr or int

The label of the line to convert to an idling line.

clear_straddlersbool, optional

Whether or not gates which straddle the line_label should also be cleared. If False and straddling gates exist, an error will be raised.

Returns

None

reverse_inplace()

Reverses the order of the circuit.

Returns

None

delete_idle_layers_inplace()

Deletes all layers in this circuit that contain no gate operations.

One of the steps of the depth_compression() method.

Returns
bool

False if the circuit is unchanged, and True otherwise.

compress_depth_inplace(one_q_gate_relations=None, verbosity=0)

Compresses the depth of this circuit using very simple re-write rules.

  1. If one_q_gate_relations is provided, all sequences of 1-qubit gates in the circuit are compressed as far as is possible using only the pair-wise combination rules provided by this dict (see below).

  2. All gates are shifted forwarded as far as is possible without any knowledge of what any of the gates are.

  3. All idle-only layers are deleted.

Parameters
one_q_gate_relationsdict

Keys that are pairs of strings, corresponding to 1-qubit gate names, with values that are a single string, also corresponding to a 1-qubit gate name. Whenever a 1-qubit gate with name name1 is followed in the circuit by a 1-qubit gate with name2 then, if one_q_gate_relations[name1,name2] = name3, name1 -> name3 and name2 -> self.identity, the identity name in the circuit. Moreover, this is still implemented when there are self.identity gates between these 1-qubit gates, and it is implemented iteratively in the sense that if there is a sequence of 1-qubit gates with names name1, name2, name3, … and there are relations for all of (name1,name2) -> name12, (name12,name3) -> name123 etc then the entire sequence of 1-qubit gates will be compressed into a single possibly non-idle 1-qubit gate followed by idle gates in place of the previous 1-qubit gates.

If a QubitProcessorSpec object has been created for the gates/device in question, the QubitProcessorSpec.oneQgate_relations is the appropriate (and auto-generated) one_q_gate_relations.

Note that this function will not compress sequences of 1-qubit gates that cannot be compressed by independently inspecting sequential non-idle pairs (as would be the case with, for example, Gxpi Gzpi Gxpi Gzpi, if the relation did not know that (Gxpi,Gzpi) -> Gypi, even though the sequence is the identity).

verbosityint, optional

If > 0, information about the depth compression is printed to screen.

Returns

None

layer(j)

Returns a tuple of the components, i.e. the (non-identity) gates, in the layer at depth j.

These are the .components of the Label returned by indexing this Circuit (using square brackets) with j, i.e. this returns this_circuit[j].components.

Parameters
jint

The index (depth) of the layer to be returned

Returns

tuple

layer_label(j)

Returns the layer, as a Label, at depth j.

This label contains as components all the (non-identity) gates in the layer..

Parameters
jint

The index (depth) of the layer to be returned

Returns

Label

layer_with_idles(j, idle_gate_name='I')

Returns a tuple of the components of the layer at depth j, with idle_gate_name at empty circuit locations.

This effectively places an explicit idle_gate_name gates wherever there is an implied identity operation in the circuit.

Parameters
jint

The index (depth) of the layer to be returned

idle_gate_namestr, optional

The idle gate name to use. Note that state space (qubit) labels will be added to this name to form a Label.

Returns

tuple

layer_label_with_idles(j, idle_gate_name='I')

Returns the layer, as a Label, at depth j, with idle_gate_name at empty circuit locations.

This effectively places an explicit idle_gate_name gates wherever there is an implied identity operation in the circuit.

Parameters
jint

The index (depth) of the layer to be returned

idle_gate_namestr, optional

The idle gate name to use. Note that state space (qubit) labels will be added to this name to form a Label.

Returns

Label

two_q_gate_count()

The number of two-qubit gates in the circuit.

(Note that this cannot distinguish between “true” 2-qubit gates and gate that have been defined to act on two qubits but that represent some tensor-product gate.)

Returns

int

num_nq_gates(nq)

The number of nq-qubit gates in the circuit.

(Note that this cannot distinguish between “true” nq-qubit gates and gate that have been defined to act on nq qubits but that represent some tensor-product gate.)

Parameters
nqint

The qubit-count of the gates to count. For example, if nq == 3, this function returns the number of 3-qubit gates.

Returns

int

format_display_str(width=80)

Formats a string for displaying this circuit suject to a maximum width.

Parameters
widthint, optional

The maximum width in characters. If the circuit is longer than this width it is wrapped using multiple lines (like a musical score).

Returns

str

convert_to_cirq(qubit_conversion, wait_duration=None, gatename_conversion=None, idle_gate_name='Gi')

Converts this circuit to a Cirq circuit.

Parameters
qubit_conversiondict

Mapping from qubit labels (e.g. integers) to Cirq qubit objects.

wait_durationcirq.Duration, optional

If no gatename_conversion dict is given, the idle operation is not converted to a gate. If wait_diration is specified and gatename_conversion is not specified, then the idle operation will be converted to a cirq.WaitGate with the specified duration.

gatename_conversiondict, optional

If not None, a dictionary that converts the gatenames in the circuit to the Cirq gates that will appear in the Cirq circuit. If only standard pyGSTi names are used (e.g., ‘Gh’, ‘Gp’, ‘Gcnot’, ‘Gcphase’, etc) this dictionary need not be specified, and an automatic conversion to the standard Cirq names will be implemented.

idle_gate_namestr, optional

Name to use for idle gates. Defaults to ‘Gi’

Returns

A Cirq Circuit object.

classmethod from_cirq(circuit, qubit_conversion=None, cirq_gate_conversion=None, remove_implied_idles=True, global_idle_replacement_label='auto')

Converts and instantiates a pyGSTi Circuit object from a Cirq Circuit object.

Parameters
circuitcirq Circuit

The cirq Circuit object to parse into a pyGSTi circuit.

qubit_conversiondict, optional (default None)

A dictionary specifying a mapping between cirq qubit objects and pyGSTi qubit labels (either integers or strings). If None, then a default mapping is created.

cirq_gate_conversiondict, optional (default None)

If specified a dictionary with keys given by cirq gate objects, and values given by pygsti gate names which overrides the built-in conversion dictionary used by default.

remove_implied_idlesbool, optional (default True)

A flag indicating whether to remove explicit idles that are part of a circuit layer containing other explicitly specified gates (i.e., whether to abide by the normal pyGSTi implicit idle convention).

global_idle_replacement_labelstring or Label or None, optional (default ‘auto’)

An option specified for the handling of global idle layers. If None, no replacement of global idle layers is performed and a verbatim conversion from the cirq layer is performed. If the string ‘auto’, then the behavior is to replace global idle layers with the gate label Label(()), which is the special syntax for the global idle layer, stylized typically as ‘[]’. If another string then replace with a gate label with the specified name acting on all of the qubits appearing in the cirq circuit. If a Label object, use this directly, this does not check for compatibility so it is up to the user to ensure the labels are compatible.

Returns
pygsti_circuit

A pyGSTi Circuit instance equivalent to the specified Cirq one.

convert_to_quil(num_qubits=None, gatename_conversion=None, qubit_conversion=None, readout_conversion=None, block_between_layers=True, block_idles=True, gate_declarations=None)

Converts this circuit to a quil string.

Parameters
num_qubitsint, optional

The number of qubits for the quil file. If None, then this is assumed to equal the number of line labels in this circuit.

gatename_conversiondict, optional

A dictionary mapping gate names contained in this circuit to the corresponding gate names used in the rendered quil. If None, a standard set of conversions is used (see standard_gatenames_quil_conversions()).

qubit_conversiondict, optional

If not None, a dictionary converting the qubit labels in the circuit to the desired qubit labels in the quil output. Can be left as None if the qubit labels are either (1) integers, or (2) of the form ‘Qi’ for integer i. In this case they are converted to integers (i.e., for (1) the mapping is trivial, for (2) the mapping strips the ‘Q’).

readout_conversiondict, optional

If not None, a dictionary converting the qubit labels mapped through qubit_conversion to the bit labels for readot. E.g. Suppose only qubit 2 (on Rigetti hardware) is in use. Then the pyGSTi string will have only one qubit (labeled 0); it will get remapped to 2 via qubit_conversion={0:2}. At the end of the quil circuit, readout should go recorded in bit 0, so readout_conversion = {0:0}. (That is, qubit with pyGSTi label 0 gets read to Rigetti bit 0, even though that qubit has Rigetti label 2.)

block_between_layersbool, optional

When True, add in a barrier after every circuit layer. Including such “pragma” blocks can be important for QCVV testing, as this can help reduce the “behind-the-scenes” compilation (beyond necessary conversion to native instructions) experience by the circuit.

block_idlesbool, optional

In the special case of global idle gates, pragma-block barriers are inserted even when block_between_layers=False. Set block_idles=False to disable this behavior, whcih typically results in global idle gates being removed by the compiler.

gate_declarationsdict, optional

If not None, a dictionary that provides unitary maps for particular gates that are not already in the quil syntax.

Returns
str

A quil string.

convert_to_openqasm(num_qubits=None, standard_gates_version='u3', gatename_conversion=None, qubit_conversion=None, block_between_layers=True, block_between_gates=False, include_delay_on_idle=True, gateargs_map=None)

Converts this circuit to an openqasm string.

Parameters
num_qubitsint, optional

The number of qubits for the openqasm file. If None, then this is assumed to equal the number of line labels in this circuit.

versionstring, optional

Either ‘u3’ or ‘x-sx-rz’. Specifies the naming convention for the QASM gates. With ‘u3’, all single-qubit gates are specified in terms of the ‘u3’ gate, used by IBM and QisKit until ~2021 (see the qasm_u3 function). With ‘x-sx-rz’, all single-gates are specified in terms of ‘x’ (an x pi rotation), ‘sx’ (an x pi/2 rotation) and ‘rz’ (a parameterized rotation around z by an angle theta).

gatename_conversiondict, optional

If not None, a dictionary that converts the gatenames in the circuit to the gatenames that will appear in the openqasm output. If only standard pyGSTi names are used (e.g., ‘Gh’, ‘Gp’, ‘Gcnot’, ‘Gcphase’, etc) this dictionary need not be specified, and an automatic conversion to the standard openqasm names will be implemented.

qubit_conversiondict, optional

If not None, a dictionary converting the qubit labels in the circuit to the desired qubit labels in the openqasm output. Can be left as None if the qubit labels are either (1) integers, or (2) of the form ‘Qi’ for integer i. In this case they are converted to integers (i.e., for (1) the mapping is trivial, for (2) the mapping strips the ‘Q’).

block_between_layersbool, optional

When True, add in a barrier after every circuit layer. Including such barriers can be important for QCVV testing, as this can help reduce the “behind-the-scenes” compilation (beyond necessary conversion to native instructions) experience by the circuit.

block_between_gates: bool, optional

When True, add in a barrier after every gate (effectively serializing the circuit). Defaults to False.

include_delay_on_idle: bool, optional

When True, includes a delay operation on implicit idles in each layer, as per Qiskit’s OpenQASM 2.0 convention after the deprecation of the id operation. Defaults to True, which is commensurate with legacy usage of this function. However, this can now be set to False to avoid this behaviour if generating actually valid OpenQASM (with no opaque delay instruction) is desired.

gateargs_mapdict, optional

If not None, a dict that maps strings (representing pyGSTi standard gate names) to functions that map the parameters of a pyGSTi gate to a string to be combined with the QASM name to specify the specific gate, in QASM. If only standard pyGSTi names are used (e.g., ‘Gh’, ‘Gzr’, ‘Gczr, etc) or none of the gates are parameterized, this dictionary need not be specified, and an automatic conversion to the standard openqasm format will be implemented.

Returns
str

An openqasm string.

simulate(model, return_all_outcomes=False)

Compute the outcome probabilities of this Circuit using model as a model for the gates.

The order of the outcome strings (e.g., ‘0100’) is w.r.t. to the ordering of the qubits in the circuit. That is, the ith element of the outcome string corresponds to the qubit with label self.line_labels[i].

Parameters
modelModel

A description of the gate and SPAM operations corresponding to the labels stored in this Circuit. If this model is over more qubits than the circuit, the output will be the probabilities for the qubits in the circuit marginalized, if possible over the other qubits. But, the simulation is over the full set of qubits in the model, and so the time taken for the simulation scales with the number of qubits in the model. For models where “spectator” qubits do not affect the qubits in this circuit (such as with perfect gates), more efficient simulations will be obtained by first creating a model only over the qubits in this circuit.

return_all_outcomesbool, optional

Whether to include outcomes in the returned dictionary that have zero probability. When False, the threshold for discarding an outcome as z ero probability is 10^-12.

Returns
probsdictionary

A dictionary with keys equal to all (return_all_outcomes is True) or possibly only some (return_all_outcomes is False) of the possible outcomes, and values that are float probabilities.

done_editing()

Make this circuit read-only, so that it can be hashed (e.g. used as a dictionary key).

This is done automatically when attempting to hash a Circuit for the first time, so there’s calling this function can usually be skipped (but it’s good for code clarity).

Returns

None

expand_instruments_and_separate_povm(model, observed_outcomes=None)

Creates a dictionary of SeparatePOVMCircuit objects from expanding the instruments of this circuit.

Each key of the returned dictionary replaces the instruments in this circuit with a selection of their members. (The size of the resulting dictionary is the product of the sizes of each instrument appearing in this circuit when observed_outcomes is None). Keys are stored as SeparatePOVMCircuit objects so it’s easy to keep track of which POVM outcomes (effects) correspond to observed data. This function is, for the most part, used internally to process a circuit before computing its outcome probabilities.

Parameters
modelModel

The model used to provide necessary details regarding the expansion, including:

  • default SPAM layers

  • definitions of instrument-containing layers

  • expansions of individual instruments and POVMs

Returns
OrderedDict

A dict whose keys are SeparatePOVMCircuit objects and whose values are tuples of the outcome labels corresponding to this circuit, one per POVM effect held in the key.

class pygsti.circuits.CircuitList(circuits, op_label_aliases=None, circuit_rules=None, circuit_weights=None, name=None)

Bases: pygsti.baseobjs.nicelyserializable.NicelySerializable

A unmutable list (a tuple) of Circuit objects and associated metadata.

Parameters

circuitslist

The list of circuits that constitutes the primary data held by this object.

op_label_aliasesdict, optional

Dictionary of circuit meta-data whose keys are operation label “aliases” and whose values are circuits corresponding to what that operation label should be expanded into before querying the dataset. Defaults to the empty dictionary (no aliases defined). e.g. op_label_aliases[‘Gx^3’] = pygsti.baseobjs.Circuit([‘Gx’,’Gx’,’Gx’])

circuit_weightsnumpy.ndarray, optional

If not None, an array of per-circuit weights (of length equal to the number of circuits) that are typically used to multiply the counts extracted for each circuit.

namestr, optional

An optional name for this list, used for status messages.

Create a CircuitList.

Parameters

circuitslist

The list of circuits that constitutes the primary data held by this object.

op_label_aliasesdict, optional

Dictionary of circuit meta-data whose keys are operation label “aliases” and whose values are circuits corresponding to what that operation label should be expanded into before querying the dataset. Defaults to the empty dictionary (no aliases defined). e.g. op_label_aliases[‘Gx^3’] = pygsti.baseobjs.Circuit([‘Gx’,’Gx’,’Gx’])

circuit_ruleslist, optional

A list of (find,replace) 2-tuples which specify circuit-label replacement rules. Both find and replace are tuples of operation labels (or Circuit objects).

circuit_weightsnumpy.ndarray, optional

If not None, an array of per-circuit weights (of length equal to the number of circuits) that are typically used to multiply the counts extracted for each circuit.

namestr, optional

An optional name for this list, used for status messages.

classmethod cast(circuits)

Convert (if needed) an object into a CircuitList.

Parameters
circuitslist or CircuitList

The object to convert.

Returns

CircuitList

apply_aliases()

Applies any operation-label aliases to this circuit list.

Returns
list

A list of Circuit objects.

truncate(circuits_to_keep)

Builds a new circuit list containing only a given subset.

This can be safer then just creating a new CircuitList because it preserves the aliases, etc., of this list.

Parameters
circuits_to_keeplist or set

The circuits to retain in the returned circuit list.

Returns

CircuitList

truncate_to_dataset(dataset)

Builds a new circuit list containing only those elements in dataset.

Parameters
datasetDataSet

The dataset to check. Aliases are applied to the circuits in this circuit list before they are tested.

Returns

CircuitList

elementvec_to_array(elementvec, layout, mergeop='sum')

Form an array of values corresponding to this CircuitList from an element vector.

An element vector holds individual-outcome elements (e.g. the bulk probabilities computed by a model).

Parameters
elementvecnumpy array

An array containting the values to use when constructing a matrix of values for this CircuitList. This array may contain more values than are needed by this CircuitList. Indices into this array are given by elindices_lookup.

layoutCircuitOutcomeProbabilityArrayLayout

The layout of elementvec, giving the mapping between its elements and circuit outcomes.

mergeop“sum” or format string, optional

Dictates how to combine the elementvec components corresponding to a single plaquette entry (circuit). If “sum”, the returned array contains summed values. If a format string, e.g. “%.2f”, then the so-formatted components are joined together with separating commas, and the resulting array contains string (object-type) entries.

Returns

numpy array

class pygsti.circuits.CircuitPlaquette(elements, num_rows=None, num_cols=None, op_label_aliases=None, circuit_rules=None)

Bases: pygsti.baseobjs.nicelyserializable.NicelySerializable

Encapsulates a single “plaquette” or “sub-matrix” within a circuit plot.

Parameters

elementsdict

A dictionary with (i,j) keys, where i and j are row and column indices and Circuit values.

num_rowsint, optional

The number of rows in this plaquette. If None, then this is set to one larger than the maximum row index in elements.

num_colsint, optional

The number of columns in this plaquette. If None, then this is set to one larger than the maximum colum index in elements.

op_label_aliasesdict, optional

A dictionary of operation label aliases that is carried along for calls to expand_aliases().

circuit_ruleslist, optional

A list of (find,replace) 2-tuples which specify string replacement rules. Both find and replace are tuples of operation labels (or Circuit objects).

Create a new CircuitPlaquette.

property circuits
elementvec_to_array(elementvec, layout, mergeop='sum')

Form a array of values corresponding to this plaquette from an element vector.

An element vector holds individual-outcome elements (e.g. the bulk probabilities computed by a model).

Parameters
elementvecnumpy array

An array containting the values to use when constructing a matrix of values for this plaquette. This array may contain more values than are needed by this plaquette. Indices into this array are given by elindices_lookup.

layoutCircuitOutcomeProbabilityArrayLayout

The layout of elementvec, giving the mapping between its elements and circuit outcomes.

mergeop“sum” or format string, optional

Dictates how to combine the elementvec components corresponding to a single plaquette entry (circuit). If “sum”, the returned array contains summed values. If a format string, e.g. “%.2f”, then the so-formatted components are joined together with separating commas, and the resulting array contains string (object-type) entries.

Returns

numpy array

process_circuits(processor_fn, updated_aliases=None)

Create a new plaquette with circuits manipulated according to processor_fn.

Parameters
processor_fnfunction

A function which takes a single Circuit argument and returns another (or the same) Circuit.

updated_aliasesdict, optional

Because the Label keys of an alias dictionary (maps Label -> Circuit) cannot be processed as a Circuit, one must supply a manualy processed alias dictionary. If you don’t use alias dictionaries just leave this set to None.

Returns

CircuitPlaquette

expand_aliases(ds_filter=None)

Returns a new CircuitPlaquette with any aliases expanded.

Aliases are expanded (i.e. applied) within the circuits of this plaquette. Optionally keeps only those strings which, after alias expansion, are in ds_filter.

Parameters
ds_filterDataSet, optional

If not None, keep only strings that are in this data set.

Returns

CircuitPlaquette

truncate(circuits_to_keep, keep_rows_cols=False)

Remove any circuits from this plaquette that aren’t in circuits_to_keep.

Parameters
circuits_to_keeplist or set

List of circuits to keep. If None, then a copy of this object is returned.

keep_rows_colsbool

Whether to retain the same number of rows as columns (even if entire rows and/or columns are empty).

Returns

CircuitPlaquette

copy()

Returns a copy of this CircuitPlaquette.

Returns

CircuitPlaquette

summary_label()
element_label(irow, icol)
class pygsti.circuits.FiducialPairPlaquette(base, fidpairs, num_rows=None, num_cols=None, op_label_aliases=None, circuit_rules=None)

Bases: CircuitPlaquette

A plaquette whose rows and columns correspond to measurement and preparation fiducial circuits.

Theese fiducials sandwich a “base” circuit.

Parameters

baseCircuit

The “base” circuit of this plaquette. Typically the sequence that is sandwiched between fiducial pairs.

fidpairslist or dict

A list or dict of (prepFiducial, effectFiducial) tuples specifying how elements is generated from base, i.e. by prepFiducial + base + effectFiducial. If a dictionary, then (i, j) keys give the row and column indices of that fiducial pair (in the case of a list, items are placed sequentially by row.

num_rowsint, optional

The number of rows in this plaquette. If None, then this is set to one larger than the maximum row index in elements.

num_colsint, optional

The number of columns in this plaquette. If None, then this is set to one larger than the maximum colum index in elements.

op_label_aliasesdict, optional

A dictionary of operation label aliases that is carried along for calls to expand_aliases().

circuit_ruleslist, optional

A list of (find,replace) 2-tuples which specify string replacement rules. Both find and replace are tuples of operation labels (or Circuit objects).

Create a new FiducialPairPlaquette.

process_circuits(processor_fn, updated_aliases=None)

Create a new plaquette with circuits manipulated according to processor_fn.

Parameters
processor_fnfunction

A function which takes a single Circuit argument and returns another (or the same) Circuit.

updated_aliasesdict, optional

Because the Label keys of an alias dictionary (maps Label -> Circuit) cannot be processed as a Circuit, one must supply a manualy processed alias dictionary. If you don’t use alias dictionaries just leave this set to None.

Returns

CircuitPlaquette

expand_aliases(ds_filter=None)

Returns a new CircuitPlaquette with any aliases expanded.

Aliases are expanded (i.e. applied) within the circuits of this plaquette. Optionally keeps only those strings which, after alias expansion, are in ds_filter.

Parameters
ds_filterDataSet, optional

If not None, keep only strings that are in this data set.

Returns

CircuitPlaquette

truncate(circuits_to_keep, keep_rows_cols=False)

Remove any circuits from this plaquette that aren’t in circuits_to_keep.

Parameters
circuits_to_keeplist or set

List of circuits to keep. If None, then a copy of this object is returned.

keep_rows_colsbool

Whether to retain the same number of rows as columns (even if entire rows and/or columns are empty).

Returns

FiducialPairPlaquette

copy()

Returns a copy of this CircuitPlaquette.

Returns

FiducialPairPlaquette

summary_label()
element_label(irow, icol)
class pygsti.circuits.GermFiducialPairPlaquette(germ, power, fidpairs, num_rows=None, num_cols=None, op_label_aliases=None, circuit_rules=None)

Bases: FiducialPairPlaquette

A plaquette whose rows and columns correspond to fiducial pairs and whose base is a germ-power.

Parameters

germCircuit

The “germ” circuit of this plaquette.

powerint

The number of times germ is repeated to get the base circuit (that is sandwiched between different fiducial pairs).

fidpairslist or dict

A list or dict of (prepStr, effectStr) tuples specifying how elements is generated from base, i.e. by prepStr + base + effectStr. If a dictionary, then (i, j) keys give the row and column indices of that fiducial pair (in the case of a list, items are placed sequentially by row.

num_rowsint, optional

The number of rows in this plaquette. If None, then this is set to one larger than the maximum row index in elements.

num_colsint, optional

The number of columns in this plaquette. If None, then this is set to one larger than the maximum colum index in elements.

op_label_aliasesdict, optional

A dictionary of operation label aliases that is carried along for calls to expand_aliases().

circuit_ruleslist, optional

A list of (find,replace) 2-tuples which specify string replacement rules. Both find and replace are tuples of operation labels (or Circuit objects).

Create a new GermFiducialPairPlaquette.

process_circuits(processor_fn, updated_aliases=None)

Create a new plaquette with circuits manipulated according to processor_fn.

Parameters
processor_fnfunction

A function which takes a single Circuit argument and returns another (or the same) Circuit.

updated_aliasesdict, optional

Because the Label keys of an alias dictionary (maps Label -> Circuit) cannot be processed as a Circuit, one must supply a manualy processed alias dictionary. If you don’t use alias dictionaries just leave this set to None.

Returns

CircuitPlaquette

expand_aliases(ds_filter=None)

Returns a new CircuitPlaquette with any aliases expanded.

Aliases are expanded (i.e. applied) within the circuits of this plaquette. Optionally keeps only those strings which, after alias expansion, are in ds_filter.

Parameters
ds_filterDataSet, optional

If not None, keep only strings that are in this data set.

Returns

CircuitPlaquette

truncate(circuits_to_keep, keep_rows_cols=False)

Remove any circuits from this plaquette that aren’t in circuits_to_keep.

Parameters
circuits_to_keeplist or set

List of circuits to keep. If None, then a copy of this object is returned.

keep_rows_colsbool

Whether to retain the same number of rows as columns (even if entire rows and/or columns are empty).

Returns

GermFiducialPairPlaquette

copy()

Returns a copy of this CircuitPlaquette.

Returns

GermFiducialPairPlaquette

summary_label()
class pygsti.circuits.PlaquetteGridCircuitStructure(plaquettes, x_values, y_values, xlabel, ylabel, additional_circuits=None, op_label_aliases=None, circuit_rules=None, circuit_weights_dict=None, additional_circuits_location='start', name=None)

Bases: pygsti.circuits.circuitlist.CircuitList

Encapsulates a set of circuits, along with an associated structure.

By “structure”, we mean the ability to index the circuits by a 4-tuple (x, y, minor_x, minor_y) for displaying in nested color box plots, along with any aliases.

Create a CircuitList.

Parameters

circuitslist

The list of circuits that constitutes the primary data held by this object.

op_label_aliasesdict, optional

Dictionary of circuit meta-data whose keys are operation label “aliases” and whose values are circuits corresponding to what that operation label should be expanded into before querying the dataset. Defaults to the empty dictionary (no aliases defined). e.g. op_label_aliases[‘Gx^3’] = pygsti.baseobjs.Circuit([‘Gx’,’Gx’,’Gx’])

circuit_ruleslist, optional

A list of (find,replace) 2-tuples which specify circuit-label replacement rules. Both find and replace are tuples of operation labels (or Circuit objects).

circuit_weightsnumpy.ndarray, optional

If not None, an array of per-circuit weights (of length equal to the number of circuits) that are typically used to multiply the counts extracted for each circuit.

namestr, optional

An optional name for this list, used for status messages.

property plaquettes
property used_xs

The x-values which have at least one non-empty plaquette

Returns

list

property used_ys

The y-values which have at least one non-empty plaquette

Returns

list

classmethod cast(circuits_or_structure)

Convert (if needed) an object into a circuit structure.

Parameters
circuits_or_structurelist or CircuitList

The object to convert. If a PlaquetteGridCircuitStructure, then the object is simply returned. Lists of circuits (including CircuitList objects are converted to structures having no plaquettes.

Returns

PlaquetteGridCircuitStructure

iter_plaquettes()
plaquette(x, y, empty_if_missing=False)

The plaquette at (x,y).

Parameters
xvarious

x-value (not index)

yvarious

y-value (not index)

empty_if_missingbool, optional

Whether an empty (0-element) plaquette should be returned when the requested (x,y) is missing.

Returns

CircuitPlaquette

truncate(circuits_to_keep=None, xs_to_keep=None, ys_to_keep=None, keep_rows_cols=True)

Truncate this circuit structure to a subset of its current circuits.

Parameters
circuits_to_keeplist

Keep only the circuits present in this list (of Circuit objects).

xs_to_keeplist, optional

The x-values to keep. If None, then all are kept.

ys_to_keeplist, optional

The y-values to keep. If None, then all are kept.

keep_rows_colsbool

Whether to retain the same number of rows as columns (even if entire rows and/or columns are empty). By default, this is True because we usually want all the plaquettes of a PlaquetteGridCircuitStructure to have the same number of rows and columns.

Returns

PlaquetteGridCircuitStructure

nested_truncations(axis='x', keep_rows_cols=False)

Get the nested truncations of this circuit structure along an axis.

When axis == ‘x’, a list of truncations (of this structure) that keep an incrementally larger set of all the x-values. E.g., if the x-values are [1,2,4], truncations to [1], [1,2], and [1,2,4] (no truncation) would be returned.

Setting axis ==’y’ gives the same behavior except using the y-values.

Parameters
axis{‘x’, ‘y’}

Which axis to truncate along (see above).

keep_rows_colsbool

Whether to retain the same number of rows as columns (even if entire rows and/or columns are empty).

Returns
list

A list of PlaquetteGridCircuitStructure objects (truncations of this object).

process_circuits(processor_fn, updated_aliases=None)

Create a new plaquette with circuits manipulated according to processor_fn.

Parameters
processor_fnfunction

A function which takes a single Circuit argument and returns another (or the same) Circuit.

updated_aliasesdict, optional

Because the Label keys of an alias dictionary (maps Label -> Circuit) cannot be processed as a Circuit, one must supply a manualy processed alias dictionary. If you don’t use alias dictionaries just leave this set to None.

Returns

PlaquetteGridCircuitStructure

copy()

Returns a copy of this circuit structure.

Returns

PlaquetteGridCircuitStructure

pygsti.circuits.create_circuits(*args, **kwargs)

Create a list of circuits using a nested loop.

Positional arguments specify evaluation strings, which are evaluated within the inner-loop for a nested loop over all list or tuple type keyword arguments.

Parameters

argslist of strings

Positional arguments are strings that python can evaluate into either a tuple of operation labels or a Circuit instance. If evaluation raises an AssertionError (an assert statement fails) then that inner loop evaluation is skipped and list construction proceeds.

kwargsdict

keys specify variable names that can be used in positional argument strings.

Returns

list of Circuit

Examples

>>> from pygsti.circuits import create_circuits
>>> As = [('a1',), ('a2',)]
>>> Bs = [('b1',), ('b2',)]
>>> list1 = create_circuits('a', 'a+b', a=As, b=Bs)
>>> print(list(map(str, list1)))
['a1', 'a2', 'a1b1', 'a1b2', 'a2b1', 'a2b2']

You can change the order in which the different iterables are advanced.

>>> list2 = create_circuits('a+b', a=As, b=Bs, order=['a', 'b'])
>>> print(list(map(str, list2)))
['a1b1', 'a1b2', 'a2b1', 'a2b2']
>>> list3 = create_circuits('a+b', a=As, b=Bs, order=['b', 'a'])
>>> print(list(map(str, list3)))
['a1b1', 'a2b1', 'a1b2', 'a2b2']
pygsti.circuits.repeat(x, num_times, assert_at_least_one_rep=False)

Repeat x num_times times.

Parameters

xtuple or Circuit

the operation sequence to repeat

num_timesint

the number of times to repeat x

assert_at_least_one_repbool, optional

if True, assert that num_times > 0. This can be useful when used within a create_circuits inner loop to build a operation sequence lists where a string must be repeated at least once to be added to the list.

Returns

tuple or Circuit (whichever x was)

pygsti.circuits.repeat_count_with_max_length(x, max_length, assert_at_least_one_rep=False)

The maximum number of times x can be repeated such that its length is <= max_length.

Parameters

xtuple or Circuit

the operation sequence to repeat

max_lengthint

the maximum length

assert_at_least_one_repbool, optional

if True, assert that number of repetitions is > 0. This can be useful when used within a create_circuits inner loop to build a operation sequence lists where a string must be repeated at least once to be added to the list.

Returns

int

the number of repetitions.

pygsti.circuits.repeat_with_max_length(x, max_length, assert_at_least_one_rep=False)

Repeat the x an integer number of times such that the result has length <= max_length.

Parameters

xtuple or Circuit

the operation sequence to repeat.

max_lengthint

the maximum length.

assert_at_least_one_repbool, optional

if True, assert that number of repetitions is > 0. This can be useful when used within a create_circuits inner loop to build a operation sequence lists where a string must be repeated at least once to be added to the list.

Returns

tuple or Circuit (whichever x was)

the repeated operation sequence

pygsti.circuits.repeat_and_truncate(x, n, assert_at_least_one_rep=False)

Repeat and truncate x to yield a sequence with exactly length n.

Repeats x so the result has length greater than n, then truncates it to have exactly length n.

Parameters

xtuple or Circuit

the operation sequence to repeat & truncate.

nint

the truncation length.

assert_at_least_one_repbool, optional

if True, assert that number of repetitions is > 0. This is always the case when x has length > 0.

Returns

tuple or Circuit (whichever x was)

the repeated-then-truncated operation sequence

pygsti.circuits.list_all_circuits(op_labels, minlength, maxlength)

List all the circuits in a given length range.

Parameters

op_labelstuple

tuple of operation labels to include in circuits.

minlengthint

the minimum circuit length to return

maxlengthint

the maximum circuit length to return

Returns

list

A list of Circuit objects.

pygsti.circuits.iter_all_circuits(op_labels, minlength, maxlength)

Iterative version of list_all_circuits()

Parameters

op_labelstuple

tuple of operation labels to include in circuits.

minlengthint

the minimum circuit length to return

maxlengthint

the maximum circuit length to return

pygsti.circuits.list_all_circuits_onelen(op_labels, length)

List all the circuits of a given length.

Parameters

op_labelstuple

tuple of operation labels to include in circuits.

lengthint

the circuit length

Returns

list

A list of Circuit objects.

pygsti.circuits.iter_all_circuits_onelen(op_labels, length)

Iterative version of list_all_circuits_onelen()

Parameters

op_labelstuple

tuple of operation labels to include in circuits.

lengthint

the circuit length

pygsti.circuits.list_all_circuits_without_powers_and_cycles(op_labels, max_length)

List all distinct aperiodic circuits up to a maximum length.

That is, list all sequences that are not a shorter gate sequence raised to a power, and are also distinct up to cycling (e.g. (‘Gx’,’Gy’,’Gy’) and (‘Gy’,’Gy’,’Gx’) are considered equivalent and only one would be included in the returned list).

Parameters

op_labelslist

A list of the operation (gate) labels to form circuits from.

max_lengthint

The maximum length strings to return. Circuits from length 1 to max_length will be returned.

Returns

list

Of Circuit objects.

pygsti.circuits.list_random_circuits_onelen(op_labels, length, count, seed=None)

Create a list of random circuits of a given length.

Parameters

op_labelstuple

tuple of operation labels to include in circuits.

lengthint

the circuit length.

countint

the number of random strings to create.

seedint, optional

If not None, a seed for numpy’s random number generator.

Returns

list of Circuits

A list of random circuits as Circuit objects.

pygsti.circuits.list_partial_circuits(circuit)

List the partial sub-circuits of circuit.

The “parital circuits” are defined as the slices circuit[0:n] for 0 <= n <= len(circuit).

Parameters

circuittuple of operation labels or Circuit

The circuit to act upon.

Returns

list of Circuit objects.

The parial circuits.

pygsti.circuits.create_lgst_circuits(prep_fiducials, meas_fiducials, op_label_src)

List the circuits required for running LGST.

Parameters

prep_fiducialslist of Circuits

The preparation fiducial circuits, used to construct an informationally complete effective preparation.

meas_fiducialslist of Circuits

The measurement fiducial circuits, used to construct an informationally complete effective measurement.

op_label_srctuple or Model

List/tuple of operation labels OR a Model whose gate and instrument labels should be used.

Returns

list of Circuit objects

The list of required circuits, without duplicates.

pygsti.circuits.list_circuits_lgst_can_estimate(dataset, prep_fiducials, meas_fiducials)

Compute the circuits that LGST is able to estimate from dataset and sets of fiducials.

Here “estimate a circuit” means that LGST can estimate the process matrix associated with that circuit.

Parameters

datasetDataSet

The data used to generate the LGST estimates

prep_fiducialslist of Circuits

The preparation fiducial circuits, used to construct an informationally complete effective preparation.

meas_fiducialslist of Circuits

The measurement fiducial circuits, used to construct an informationally complete effective measurement.

Returns

list of lists of tuples

each list of tuples specifyies a circuit that LGST can estimate.

pygsti.circuits.to_circuits(list_of_op_label_tuples_or_strings, line_labels='auto')

Converts a list of operation label tuples or strings to a list of Circuit objects.

Parameters

list_of_op_label_tuples_or_stringslist

List which may contain a mix of Circuit objects, tuples of gate labels, and strings in standard-text-format.

line_labels“auto” or tuple, optional

The line labels to use when creating Circuit objects from non-Circuit elements of list_of_op_label_tuples_or_strings. If “auto” then the line labels are determined automatically based on the line-labels which are present in the layer labels.

Returns

list of Circuit objects

Each item of list_of_op_label_tuples_or_strings converted to a Circuit.

pygsti.circuits.translate_circuit(circuit, alias_dict)

Translates circuit according to the aliases in alias_dict.

Creates a new Circuit object from an existing one by replacing operation labels in circuit by (possibly multiple) new labels according to alias_dict.

Parameters

circuitCircuit

The circuit to use as the base for find & replace operations.

alias_dictdict

A dictionary whose keys are single operation labels and whose values are lists or tuples of the new operation labels that should replace that key. If alias_dict is None then circuit is returned.

Returns

Circuit

pygsti.circuits.translate_circuits(circuits, alias_dict)

Applies translate_circuit() to each element of circuits.

Creates a new list of Circuit objects from an existing one by replacing operation labels in circuits by (possibly multiple) new labels according to alias_dict.

Parameters

circuitslist of Circuits

The list of circuits to use as the base for find & replace operations.

alias_dictdict

A dictionary whose keys are single operation labels and whose values are lists or tuples of the new operation labels that should replace that key. If alias_dict is None then circuits is returned.

Returns

list of Circuits

pygsti.circuits.manipulate_circuit(circuit, rules, line_labels='auto')

Manipulates a Circuit object according to rules.

Each element of rules is of the form (find,replace), and specifies a replacement rule. For example, (‘A’,), (‘B’,’C’) simply replaces each A with B,C. (‘A’, ‘B’), (‘A’, ‘B2’)) replaces B with B2 when it follows A. (‘B’, ‘A’), (‘B2’, ‘A’)) replaces B with B2 when it precedes A.

Parameters

circuitCircuit or tuple

The circuit to manipulate.

ruleslist

A list of (find,replace) 2-tuples which specify the replacement rules. Both find and replace are tuples of operation labels (or Circuit objects). If rules is None then circuit is returned.

line_labels“auto” or tuple, optional

The line labels to use when creating a the output Circuit objects. If “auto” then the line labels are determined automatically based on the line-labels which are present in the corresponding layer labels.

Returns

list of Circuits

pygsti.circuits.manipulate_circuits(circuits, rules, line_labels='auto')

Applies manipulate_circuit() to each element of circuits.

This creates a new list of Circuit objects from an existing one by performing replacements according to rules (see manipulate_circuit()).

Parameters

circuitslist of Circuits

The list of circuits to use as the base for find & replace operations.

ruleslist

A list of (find,replace) 2-tuples which specify the replacement rules. Both find and replace are tuples of operation labels (or Circuit objects). If rules is None then circuits is returned.

line_labels“auto” or tuple, optional

The line labels to use when creating output Circuit objects. If “auto” then the line labels are determined automatically based on the line-labels which are present in the corresponding layer labels.

Returns

list of Circuits

pygsti.circuits.filter_circuits(circuits, sslbls_to_keep, new_sslbls=None, drop=False, idle=())

Applies filter_circuit() to each element of circuits.

Removes any labels from circuits whose state-space labels are not entirely in sslbls_to_keep. If a gates label’s state-space labels (its .sslbls) is None, then the label is retained in the returned string.

Furthermore, by specifying new_sslbls one can map the state-space labels in sslbls_to_keep to new labels (useful for “re-basing” a set of qubit strings.

Parameters

circuitslist

A list of circuits to act on.

sslbls_to_keeplist

A list of state space labels specifying which operation labels should be retained.

new_sslblslist, optional

If not None, a list of the same length as sslbls_to_keep specifying a new set of state space labels to replace those in sslbls_to_keep.

dropbool, optional

If True, then non-empty circuits which become empty after filtering are not included in (i.e. dropped from) the returned list. If False, then the returned list is always the same length as the input list.

idlestring or Label, optional

The operation label to be used when there are no kept components of a “layer” (element) of a circuit.

Returns

list

A list of Circuits

pygsti.circuits.filter_circuit(circuit, sslbls_to_keep, new_sslbls=None, idle=())

Filters circuit by keeping only a subset of its “lines” (i.e. state space labels, often qubits).

Removes any labels from circuit whose state-space labels are not entirely in sslbls_to_keep. If a gates label’s state-space labels (its .sslbls) is None, then the label is retained in the returned string.

Furthermore, by specifying new_sslbls one can map the state-space labels in sslbls_to_keep to new labels (useful for “re-basing” a set of qubit strings.

Parameters

circuitCircuit

The circuit to act on.

sslbls_to_keeplist

A list of state space labels specifying which operation labels should be retained.

new_sslblslist, optional

If not None, a list of the same length as sslbls_to_keep specifying a new set of state space labels to replace those in sslbls_to_keep.

idlestring or Label, optional

The operation label to be used when there are no kept components of a “layer” (element) of circuit.

Returns

Circuit

pygsti.circuits.RANK_TOL = '1e-09'
pygsti.circuits.create_cloudnoise_circuits(processor_spec, max_lengths, single_q_fiducials, max_idle_weight=1, maxhops=0, extra_weight_1_hops=0, extra_gate_weight=0, parameterization='H+S', verbosity=0, cache=None, idle_only=False, idt_pauli_dicts=None, algorithm='greedy', idle_op_str=((),), comm=None)

Constructs a set of circuits that amplify all the parameters of a clould-noise model.

Create a set of fiducial1+germ^power+fiducial2 sequences which amplify all of the parameters of a CloudNoiseModel created by passing the arguments of this function to function:create_cloudnoise_model_from_hops_and_weights.

Note that this function essentialy performs fiducial selection, germ selection, and fiducial-pair reduction simultaneously. It is used to generate a short (ideally minimal) list of sequences needed for multi- qubit GST.

Parameters

processor_specProcessorSpec

Defines the prcoessor interface (API) for which circuits are created. This API includes the number of qubits and their labels, gate names, qubit geometry or gate availability, etc.

max_lengthslist

A list of integers specifying the different maximum lengths for germ powers. Typically these values start a 1 and increase by powers of 2, e.g. [1,2,4,8,16].

single_q_fiducialslist

A list of gate-name-tuples, e.g. [(), (‘Gx’,), (‘Gy’,), (‘Gx’,’Gx’)], which form a set of 1-qubit fiducials for the given model (compatible with both the gates it posseses and their parameterizations - for instance, only [(), (‘Gx’,), (‘Gy’,)] is needed for just Hamiltonian and Stochastic errors. If a list of two such lists is given, they specify preparation and measurement fiducials, respectively, e.g. [ [(), (‘Gx’,), (‘Gx’,’Gz’)], [(), (‘Gx’,), (‘Gz’,’Gx’)] ].

max_idle_weightint, optional

The maximum-weight for errors on the global idle gate.

maxhopsint

The locality constraint: for a gate, errors (of weight up to the maximum weight for the gate) are allowed to occur on the gate’s target qubits and those reachable by hopping at most maxhops times from a target qubit along nearest-neighbor links (defined by the geometry).

extra_weight_1_hopsint, optional

Additional hops (adds to maxhops) for weight-1 errors. A value > 0 can be useful for allowing just weight-1 errors (of which there are relatively few) to be dispersed farther from a gate’s target qubits. For example, a crosstalk-detecting model might use this.

extra_gate_weightint, optional

Addtional weight, beyond the number of target qubits (taken as a “base weight” - i.e. weight 2 for a 2Q gate), allowed for gate errors. If this equals 1, for instance, then 1-qubit gates can have up to weight-2 errors and 2-qubit gates can have up to weight-3 errors.

parameterization{“CPTP”, “H+S+A”, “H+S”, “S”, “H+D+A”, “D+A”, “D”}

The parameterization used to define which parameters need to be amplified.

verbosityint, optional

The level of detail printed to stdout. 0 means silent.

cachedict, optional

A cache dictionary which holds template information so that repeated calls to create_cloudnoise_circuits can draw on the same pool of templates.

idle_onlybool, optional

If True, only sequences for the idle germ are returned. This is useful for idle tomography in particular.

idt_pauli_dictstuple, optional

A (prepDict,measDict) tuple of dicts that maps a 1-qubit Pauli basis string (e.g. ‘X’ or ‘-Y’) to a sequence of gate names. If given, the idle-germ fiducial pairs chosen by this function are restricted to those where either 1) each qubit is prepared and measured in the same basis or 2) each qubits is prepared and measured in different bases (note: ‘-X’ and ‘X” are considered the same basis). This restriction makes the resulting sequences more like the “standard” ones of idle tomography, and thereby easier to interpret.

algorithm{“greedy”,”sequential”}

The algorithm is used internall by _find_amped_polynomials_for_syntheticidle(). You should leave this as the default unless you know what you’re doing.

idle_op_strCircuit or tuple, optional

The circuit or label that is used to indicate a completely idle layer (all qubits idle).

commmpi4py.MPI.Comm, optional

When not None, an MPI communicator for distributing the computation across multiple processors.

Returns

PlaquetteGridCircuitStructure

An object holding a structured (using germ and fiducial sub-sequences) list of circuits.

pygsti.circuits.create_kcoverage_template(n, k, verbosity=0)

Construct a template for how to create a “k-coverage” set of length-n sequences.

Consider a set of length-n words from a k-letter alphabet. These words (sequences of letters) have the “k-coverage” property if, for any choice of k different letter positions (indexed from 0 to n-1), every permutation of the k distinct letters (symbols) appears in those positions for at least one element (word) in the set. Such a set of sequences is returned by this function, namely a list length-n lists containing the integers 0 to k-1.

This notion has application to idle-gate fiducial pair tiling, when we have found a set of fiducial pairs for k qubits and want to find a set of sequences on n > k qubits such that any subset of k qubits experiences the entire set of (k-qubit) fiducial pairs. Simply take the k-coverage template and replace the letters (0 to k-1) with the per-qubit 1Q pieces of each k-qubit fiducial pair.

Parameters

nint

The sequences length (see description above).

kint

The coverage number (see description above).

verbosityint, optional

Amount of detail to print to stdout.

Returns

list

A list of length-n lists containing the integers 0 to k-1. The length of the outer lists depends on the particular values of n and k and is not guaranteed to be minimal.

pygsti.circuits.make_lsgst_structs(op_label_src, prep_strs, effect_strs, germ_list, max_length_list, fid_pairs=None, trunc_scheme='whole germ powers', nest=True, keep_fraction=1, keep_seed=None, include_lgst=True, op_label_aliases=None, sequence_rules=None, dscheck=None, action_if_missing='raise', germ_length_limits=None, verbosity=0)

Deprecated function.

pygsti.circuits.create_lsgst_circuit_lists(op_label_src, prep_fiducials, meas_fiducials, germs, max_lengths, fid_pairs=None, trunc_scheme='whole germ powers', nest=True, keep_fraction=1, keep_seed=None, include_lgst=True, op_label_aliases=None, circuit_rules=None, dscheck=None, action_if_missing='raise', germ_length_limits=None, verbosity=0)

Create a set of long-sequence GST circuit lists (including structure).

Constructs a series (a list) of circuit structures used by long-sequence GST (LSGST) algorithms. If include_lgst == True then the starting structure contains the LGST strings, otherwise the starting structure is empty. For each nonzero element of max_length_list, call it L, a set of circuits is created with the form:

Case: trunc_scheme == ‘whole germ powers’:

prep_fiducial + pygsti.circuits.repeat_with_max_length(germ,L) + meas_fiducial

Case: trunc_scheme == ‘truncated germ powers’:

prep_fiducial + pygsti.circuits.repeat_and_truncate(germ,L) + meas_fiducial

Case: trunc_scheme == ‘length as exponent’:

prep_fiducial + germ^L + meas_fiducial

If nest == True, the above set is iteratively added (w/duplicates removed) to the current circuit structure to form a final structure for the given L. This results in successively larger structures, each of which contains all the elements of previous-L structures. If nest == False then the above set is the final structure for the given L.

Parameters

op_label_srclist or Model

List of operation labels to determine needed LGST circuits. If a Model, then the model’s gate and instrument labels are used. Only relevant when include_lgst == True.

prep_fiducialslist of Circuits

List of the preparation fiducial circuits, which follow state preparation.

effect_fiducialslist of Circuits

List of the measurement fiducial circuits, which precede measurement.

germslist of Circuits

List of the germ circuits.

max_lengthslist of ints

List of maximum lengths. A zero value in this list has special meaning, and corresponds to the LGST circuits.

fid_pairslist of 2-tuples or dict, optional

Specifies a subset of all fiducial string pairs (prepStr, effectStr) to be used in the circuit lists. If a list, each element of fid_pairs is a (iPrepStr, iEffectStr) 2-tuple of integers, each indexing a string within prep_strs and effect_strs, respectively, so that prepStr = prep_strs[iPrepStr] and effectStr = effect_strs[iEffectStr]. If a dictionary, keys are germs (elements of germ_list) and values are lists of 2-tuples specifying the pairs to use for that germ.

trunc_schemestr, optional

Truncation scheme used to interpret what the list of maximum lengths means. If unsure, leave as default. Allowed values are:

  • ‘whole germ powers’ – germs are repeated an integer number of times such that the length is less than or equal to the max.

  • ‘truncated germ powers’ – repeated germ string is truncated to be exactly equal to the max (partial germ at end is ok).

  • ‘length as exponent’ – max. length is instead interpreted as the germ exponent (the number of germ repetitions).

nestboolean, optional

If True, the returned circuit lists are “nested”, meaning that each successive list of circuits contains all the gate strings found in previous lists (and usually some additional new ones). If False, then the returned string list for maximum length == L contains only those circuits specified in the description above, and not those for previous values of L.

keep_fractionfloat, optional

The fraction of fiducial pairs selected for each germ-power base string. The default includes all fiducial pairs. Note that for each germ-power the selected pairs are different random sets of all possible pairs (unlike fid_pairs, which specifies the same fiducial pairs for all same-germ base strings). If fid_pairs is used in conjuction with keep_fraction, the pairs specified by fid_pairs are always selected, and any additional pairs are randomly selected.

keep_seedint, optional

The seed used for random fiducial pair selection (only relevant when keep_fraction < 1).

include_lgstboolean, optional

If true, then the starting list (only applicable when nest == True) is the list of LGST strings rather than the empty list. This means that when nest == True, the LGST circuits will be included in all the lists.

op_label_aliasesdictionary, optional

Dictionary whose keys are operation label “aliases” and whose values are tuples corresponding to what that operation label should be expanded into before querying the dataset. This information is stored within the returned circuit structures. Defaults to the empty dictionary (no aliases defined) e.g. op_label_aliases[‘Gx^3’] = (‘Gx’,’Gx’,’Gx’)

circuit_ruleslist, optional

A list of (find,replace) 2-tuples which specify string replacement rules. Both find and replace are tuples of operation labels (or Circuit objects).

dscheckDataSet, optional

A data set which is checked for each of the generated circuits. When a generated circuit is missing from this DataSet, action is taken according to action_if_missing.

action_if_missing{“raise”,”drop”}, optional

The action to take when a generated circuit is missing from dscheck (only relevant when dscheck is not None). “raise” causes a ValueError to be raised; “drop” causes the missing circuits to be dropped from the returned set.

germ_length_limitsdict, optional

A dictionary limiting the max-length values used for specific germs. Keys are germ circuits and values are integers. For example, if this argument is {(‘Gx’,): 4} and max_length_list = [1,2,4,8,16], then the germ (‘Gx’,) is only repeated using max-lengths of 1, 2, and 4 (whereas other germs use all the values in max_length_list).

verbosityint, optional

The level of output to print to stdout.

Returns

list of PlaquetteGridCircuitStructure objects

The i-th object corresponds to a circuit list containing repeated germs limited to length max_length_list[i]. If nest == True, then repeated germs limited to previous max-lengths are also included. Note that a “0” maximum-length corresponds to the LGST strings.

pygsti.circuits.create_lsgst_circuits(op_label_src, prep_strs, effect_strs, germ_list, max_length_list, fid_pairs=None, trunc_scheme='whole germ powers', keep_fraction=1, keep_seed=None, include_lgst=True)

List all the circuits (i.e. experiments) required for long-sequence GST (LSGST).

Returns a single list containing, without duplicates, all the gate strings required throughout all the iterations of LSGST given by max_length_list. Thus, the returned list is equivalently the list of the experiments required to run LSGST using the supplied parameters, and so commonly used when construting data set templates or simulated data sets. The breakdown of which circuits are used for which iteration(s) of LSGST is given by create_lsgst_circuit_lists(…).

Parameters

op_label_srclist or Model

List of operation labels to determine needed LGST strings. If a Model, then the model’s gate and instrument labels are used. Only relevant when include_lgst == True.

prep_strslist of Circuits

List of the preparation fiducial circuits, which follow state preparation.

effect_strslist of Circuits

List of the measurement fiducial circuits, which precede measurement.

germ_listlist of Circuits

List of the germ circuits.

max_length_listlist of ints

List of maximum lengths.

fid_pairslist of 2-tuples, optional

Specifies a subset of all fiducial string pairs (prepStr, effectStr) to be used in the circuit lists. If a list, each element of fid_pairs is a (iPrepStr, iEffectStr) 2-tuple of integers, each indexing a string within prep_strs and effect_strs, respectively, so that prepStr = prep_strs[iPrepStr] and effectStr = effect_strs[iEffectStr]. If a dictionary, keys are germs (elements of germ_list) and values are lists of 2-tuples specifying the pairs to use for that germ.

trunc_schemestr, optional

Truncation scheme used to interpret what the list of maximum lengths means. If unsure, leave as default. Allowed values are:

  • ‘whole germ powers’ – germs are repeated an integer number of times such that the length is less than or equal to the max.

  • ‘truncated germ powers’ – repeated germ string is truncated to be exactly equal to the max (partial germ at end is ok).

  • ‘length as exponent’ – max. length is instead interpreted as the germ exponent (the number of germ repetitions).

keep_fractionfloat, optional

The fraction of fiducial pairs selected for each germ-power base string. The default includes all fiducial pairs. Note that for each germ-power the selected pairs are different random sets of all possible pairs (unlike fid_pairs, which specifies the same fiduicial pairs for all same-germ base strings). If fid_pairs is used in conjuction with keep_fraction, the pairs specified by fid_pairs are always selected, and any additional pairs are randomly selected.

keep_seedint, optional

The seed used for random fiducial pair selection (only relevant when keep_fraction < 1).

include_lgstboolean, optional

If true, then ensure that LGST sequences are included in the returned list.

Returns

PlaquetteGridCircuitStructure

pygsti.circuits.create_elgst_lists(op_label_src, germ_list, max_length_list, trunc_scheme='whole germ powers', nest=True, include_lgst=True)

Create a set of circuit lists for eLGST based on germs and max-lengths

Constructs a series (a list) of circuit lists used by the extended LGST (eLGST) algorithm. If include_lgst == True then the starting list is the list of length-1 operation label strings, otherwise the starting list is empty. For each nonzero element of max_length_list, call it L, a list of circuits is created with the form:

Case: trunc_scheme == ‘whole germ powers’:

pygsti.circuits.repeat_with_max_length(germ,L)

Case: trunc_scheme == ‘truncated germ powers’:

pygsti.circuits.repeat_and_truncate(germ,L)

Case: trunc_scheme == ‘length as exponent’:

germ^L

If nest == True, the above list is iteratively added (w/duplicates removed) to the current list of circuits to form a final list for the given L. This results in successively larger lists, each of which contains all the elements of previous-L lists. If nest == False then the above list is the final list for the given L.

Parameters

op_label_srclist or Model

List of operation labels to determine needed LGST strings. If a Model, then the model’s gate and instrument labels are used. Only relevant when include_lgst == True.

germ_listlist of Circuits

List of the germ circuits.

max_length_listlist of ints

List of maximum lengths. A zero value in this list has special meaning, and corresponds to the length-1 operation label strings.

trunc_schemestr, optional

Truncation scheme used to interpret what the list of maximum lengths means. If unsure, leave as default. Allowed values are:

  • ‘whole germ powers’ – germs are repeated an integer number of times such that the length is less than or equal to the max.

  • ‘truncated germ powers’ – repeated germ string is truncated to be exactly equal to the max (partial germ at end is ok).

  • ‘length as exponent’ – max. length is instead interpreted as the germ exponent (the number of germ repetitions).

nestboolean, optional

If True, the returned circuit lists are “nested”, meaning that each successive list of circuits contains all the gate strings found in previous lists (and usually some additional new ones). If False, then the returned string list for maximum length == L contains only those circuits specified in the description above, and not those for previous values of L.

include_lgstboolean, optional

If true, then the starting list (only applicable when nest == True) is the list of length-1 operation label strings rather than the empty list. This means that when nest == True, the length-1 sequences will be included in all the lists.

Returns

list of (lists of Circuits)

The i-th list corresponds to a circuit list containing repeated germs limited to length max_length_list[i]. If nest == True, then repeated germs limited to previous max-lengths are also included. Note that a “0” maximum-length corresponds to the gate label strings.

pygsti.circuits.create_elgst_experiment_list(op_label_src, germ_list, max_length_list, trunc_scheme='whole germ powers', include_lgst=True)

List of all the circuits (i.e. experiments) required for extended LGST (eLGST).

Returns a single list containing, without duplicates, all the gate strings required throughout all the iterations of eLGST given by max_length_list. Thus, the returned list is equivalently the list of the experiments required to run eLGST using the supplied parameters, and so commonly used when construting data set templates or simulated data sets. The breakdown of which circuits are used for which iteration(s) of eLGST is given by create_elgst_lists(…).

Parameters

op_label_srclist or Model

List of operation labels to determine needed LGST strings. If a Model, then the model’s gate and instrument labels are used. Only relevant when include_lgst == True.

germ_listlist of Circuits

List of the germ circuits.

max_length_listlist of ints

List of maximum lengths. A zero value in this list has special meaning, and corresponds to the length-1 operation label strings.

trunc_schemestr, optional

Truncation scheme used to interpret what the list of maximum lengths means. If unsure, leave as default. Allowed values are:

  • ‘whole germ powers’ – germs are repeated an integer number of times such that the length is less than or equal to the max.

  • ‘truncated germ powers’ – repeated germ string is truncated to be exactly equal to the max (partial germ at end is ok).

  • ‘length as exponent’ – max. length is instead interpreted as the germ exponent (the number of germ repetitions).

include_lgstboolean, optional

If true, then ensure that length-1 sequences are included in the returned list.

Returns

list of Circuits