pygsti.models.gaugegroup.TrivialGaugeGroup

pygsti.models.gaugegroup.TrivialGaugeGroup#

class TrivialGaugeGroup(state_space)#

Bases: GaugeGroup

A trivial gauge group with no degrees of freedom.

Useful for telling pyGSTi that you don’t want to do any gauge optimization within the framework common to the other gauge groups. Using a TrivialGaugeGroup instead of None in gauge optimization will prevent pyGSTi from wondering if you meant to not-gauge-optimize and displaying warning messages.

Parameters:

state_space (StateSpace) – The state space for this gauge group. This is the state space that elements of the gauge group act on. This should be the same as mdl.state_space where mdl is a Model you want to gauge-transform.

Creates a new gauge group object

Parameters:

  • name (str) – A name for this group - used for reporting what type of gauge optimization was performed.

  • state_space (_StateSpace)

Methods

__init__(state_space)

Creates a new gauge group object

add_mongodb_write_ops(write_ops, mongodb[, ...])

Accumulate write and update operations for writing this object to a MongoDB database.

compute_element(param_vec)

Retrieve the element of this group corresponding to param_vec

dump(f[, format])

Serializes and writes this object to a given output stream.

dumps([format])

Serializes this object and returns it as a string.

from_mongodb(mongodb, doc_id, **kwargs)

Create and initialize an object from a MongoDB instance.

from_mongodb_doc(mongodb, collection_name, ...)

Create and initialize an object from a MongoDB instance and pre-loaded primary document.

from_nice_serialization(state)

Create and initialize an object from a "nice" serialization.

load(f[, format])

Load an object of this type, or a subclass of this type, from an input stream.

loads(s[, format])

Load an object of this type, or a subclass of this type, from a string.

read(path[, format])

Read an object of this type, or a subclass of this type, from a file.

remove_from_mongodb(mongodb, doc_id[, ...])

Remove the documents corresponding to an instance of this class from a MongoDB database.

remove_me_from_mongodb(mongodb[, session, ...])

to_nice_serialization()

Serialize this object in a way that adheres to "niceness" rules of common text file formats.

write(path, **format_kwargs)

Writes this object to a file.

write_to_mongodb(mongodb[, session, ...])

Write this object to a MongoDB database.

Attributes

collection_name

initial_params

Return a good (or standard) starting parameter vector, used to initialize a gauge optimization.

num_params

Return the number of parameters (degrees of freedom) of this gauge group.
add_mongodb_write_ops(write_ops, mongodb, overwrite_existing=False, **kwargs)#

Accumulate write and update operations for writing this object to a MongoDB database.

Similar to write_to_mongodb() but collects write operations instead of actually executing any write operations on the database. This function may be preferred to write_to_mongodb() when this object is being written as a part of a larger entity and executing write operations is saved until the end.

As in write_to_mongodb(), self.collection_name is the collection name and _id is either: 1) the ID used by a previous write or initial read-in, if one exists, OR 2) a new random bson.objectid.ObjectId

Parameters:

  • write_ops (WriteOpsByCollection) – An object that keeps track of pymongo write operations on a per-collection basis. This object accumulates write operations to be performed at some point in the future.

  • mongodb (pymongo.database.Database) – The MongoDB instance to write data to.

  • overwrite_existing (bool, optional) – Whether existing documents should be overwritten. The default of False causes a ValueError to be raised if a document with the given _id already exists and is different from what is being written.

  • **kwargs (dict) – Additional keyword arguments potentially used by subclass implementations. Any arguments allowed by a subclass’s _add_auxiliary_write_ops_and_update_doc method is allowed here.

Returns:

The identifier (_id value) of the main document that was written.

Return type:

bson.objectid.ObjectId

compute_element(param_vec)#

Retrieve the element of this group corresponding to param_vec

Parameters:

param_vec (numpy.ndarray) – A 1D array of length num_params().

Return type:

TrivialGaugeGroupElement

dump(f, format='json', **format_kwargs)#

Serializes and writes this object to a given output stream.

Parameters:

  • f (file-like) – A writable output stream.

  • format ({'json', 'repr'}) – The format to write.

  • format_kwargs (dict, optional) – Additional arguments specific to the format being used. For example, the JSON format accepts indent as an argument because json.dump does.

Return type:

None

dumps(format='json', **format_kwargs)#

Serializes this object and returns it as a string.

Parameters:

  • format ({'json', 'repr'}) – The format to write.

  • format_kwargs (dict, optional) – Additional arguments specific to the format being used. For example, the JSON format accepts indent as an argument because json.dump does.

Return type:

str

classmethod from_mongodb(mongodb, doc_id, **kwargs)#

Create and initialize an object from a MongoDB instance.

Parameters:

  • mongodb (pymongo.database.Database) – The MongoDB instance to load from.

  • doc_id (bson.objecctid.ObjectId or dict) – The object ID or filter used to find a single object ID within the database. This document is loaded from the collection given by the collection_name attribute of this class.

  • **kwargs (dict) – Additional keyword arguments potentially used by subclass implementations. Any arguments allowed by a subclass’s _create_obj_from_doc_and_mongodb method is allowed here.

Return type:

object

classmethod from_mongodb_doc(mongodb, collection_name, doc, **kwargs)#

Create and initialize an object from a MongoDB instance and pre-loaded primary document.

Parameters:

  • mongodb (pymongo.database.Database) – The MongoDB instance to load from.

  • collection_name (str) – The collection name within mongodb that doc was loaded from. This is needed for the sole purpose of setting the created (returned) object’s database “coordinates”.

  • doc (dict) – The already-retrieved main document for the object being loaded. This takes the place of giving an identifier for this object.

  • **kwargs (dict) – Additional keyword arguments potentially used by subclass implementations. Any arguments allowed by a subclass’s _create_obj_from_doc_and_mongodb method is allowed here.

Return type:

object

classmethod from_nice_serialization(state)#

Create and initialize an object from a “nice” serialization.

A “nice” serialization here means one created by a prior call to to_nice_serialization using this class or a subclass of it. Nice serializations adhere to additional rules (e.g. that dictionary keys must be strings) that make them amenable to common file formats (e.g. JSON).

The state argument is typically a dictionary containing ‘module’ and ‘state’ keys specifying the type of object that should be created. This type must be this class or a subclass of it.

Parameters:

state (object) – An object, usually a dictionary, representing the object to de-serialize.

Return type:

object

classmethod load(f, format='json')#

Load an object of this type, or a subclass of this type, from an input stream.

Parameters:

  • f (file-like) – An open input stream to read from.

  • format ({'json'}) – The format of the input stream data.

Return type:

NicelySerializable

classmethod loads(s, format='json')#

Load an object of this type, or a subclass of this type, from a string.

Parameters:

  • s (str) – The serialized object.

  • format ({'json'}) – The format of the string data.

Return type:

NicelySerializable

classmethod read(path, format=None)#

Read an object of this type, or a subclass of this type, from a file.

Parameters:

  • path (str or Path or file-like) – The filename to open or an already open input stream.

  • format ({'json', None}) – The format of the file. If None this is determined automatically by the filename extension of a given path.

Return type:

NicelySerializable

classmethod remove_from_mongodb(mongodb, doc_id, collection_name=None, session=None, recursive='default')#

Remove the documents corresponding to an instance of this class from a MongoDB database.

Parameters:

  • mongodb (pymongo.database.Database) – The MongoDB instance to remove documents from.

  • doc_id (bson.objectid.ObjectId) – The identifier of the root document stored in the database.

  • collection_name (str, optional) – the MongoDB collection within mongodb where the main document resides. If None, then <this_class>.collection_name is used (which is usually what you want).

  • session (pymongo.client_session.ClientSession, optional) – MongoDB session object to use when interacting with the MongoDB database. This can be used to implement transactions among other things.

  • recursive (RecursiveRemovalSpecification, optional) – An object that filters the type of documents that are removed. Used when working with inter-related experiment designs, data, and results objects to only remove the types of documents you know aren’t being shared with other documents.

Return type:

None

to_nice_serialization()#

Serialize this object in a way that adheres to “niceness” rules of common text file formats.

Returns:

Usually a dictionary representing the serialized object, but may also be another native Python type, e.g. a string or list.

Return type:

object

write(path, **format_kwargs)#

Writes this object to a file.

Parameters:

  • path (str or Path) – The name of the file that is written.

  • format_kwargs (dict, optional) – Additional arguments specific to the format being used. For example, the JSON format accepts indent as an argument because json.dump does.

Return type:

None

write_to_mongodb(mongodb, session=None, overwrite_existing=False, **kwargs)#

Write this object to a MongoDB database.

The collection name used is self.collection_name, and the _id is either: 1) the ID used by a previous write or initial read-in, if one exists, OR 2) a new random bson.objectid.ObjectId

Parameters:

  • mongodb (pymongo.database.Database) – The MongoDB instance to write data to.

  • session (pymongo.client_session.ClientSession, optional) – MongoDB session object to use when interacting with the MongoDB database. This can be used to implement transactions among other things.

  • overwrite_existing (bool, optional) – Whether existing documents should be overwritten. The default of False causes a ValueError to be raised if a document with the given _id already exists and is different from what is being written.

  • **kwargs (dict) – Additional keyword arguments potentially used by subclass implementations. Any arguments allowed by a subclass’s _add_auxiliary_write_ops_and_update_doc method is allowed here.

Returns:

The identifier (_id value) of the main document that was written.

Return type:

bson.objectid.ObjectId

property initial_params: ndarray#

Return a good (or standard) starting parameter vector, used to initialize a gauge optimization.

Returns:

A 1D array of length num_params().

Return type:

numpy.ndarray

property num_params: int#

Return the number of parameters (degrees of freedom) of this gauge group.

Return type:

int