pygsti.objects.TPParameterizedSPAMVec

class pygsti.objects.TPParameterizedSPAMVec(vec)

Encapsulates a SPAM vector that is fully parameterized except for the first element, which is frozen to be 1/(d**0.25). This is so that, when the SPAM vector is interpreted in the Pauli or Gell-Mann basis, the represented density matrix has trace == 1. This restriction is frequently used in conjuction with trace-preserving (TP) gates.

__init__(vec)

Initialize a TPParameterizedSPAMOp object.

Parameters:vec (array_like or SPAMVec) – a 1D numpy array representing the SPAM operation. The shape of this array sets the dimension of the SPAM op.

Methods

__init__(vec) Initialize a TPParameterizedSPAMOp object.
convert_to_vector(V) Static method that converts a vector-like object to a 2D numpy dim x 1 column array.
copy() Copy this SPAM vector.
deriv_wrt_params() Construct a matrix whose columns are the derivatives of the SPAM vector with respect to a single param.
from_vector(v) Initialize the SPAM vector using a 1D array of parameters.
get_dimension() Return the dimension of the gate matrix.
num_params() Get the number of independent parameters which specify this SPAM vector.
set_vector(vec) Attempts to modify SPAMVec parameters so that the specified raw SPAM vector becomes vec.
to_vector() Get the SPAM vector parameters as an array of values.