pygsti.objects.GateSet.hproduct¶
-
GateSet.
hproduct
(gatestring, flat=False)¶ Compute the hessian of a specified sequence of gate labels.
Parameters: - gatestring (GateString or tuple of gate labels) – The sequence of gate labels.
- flat (bool, optional) – Affects the shape of the returned derivative array (see below).
Returns: hessian – * if flat == False, a M x M x G x G numpy array, where:
- M == length of the vectorized gateset (number of gateset parameters)
- G == the linear dimension of a gate matrix (G x G gate matrices).
and hessian[i,j,k,l] holds the derivative of the (k,l)-th entry of the product with respect to the j-th then i-th gateset parameters.
if flat == True, a N x M x M numpy array, where:
- N == the number of entries in a single flattened gate (ordered as numpy.flatten)
- M == length of the vectorized gateset (number of gateset parameters)
and hessian[i,j,k] holds the derivative of the i-th entry of the flattened product with respect to the k-th then k-th gateset parameters.
Return type: numpy array