qstack.mathutils.matrix¶

Matrix operation utility functions.

qstack.mathutils.matrix.from_tril(mat_tril)[source]¶

Restore a symmetric matrix from its lower-triangular form.

Parameters:: mat_tril (numpy.ndarray) – 1D array containing matrix in lower-triangular form.
Returns:: 2D symmetric matrix.
Return type:: numpy.ndarray

qstack.mathutils.matrix.sqrtm(m, eps=1e-13)[source]¶

Compute the matrix square root of a symmetric matrix.

Parameters:

m (numpy.ndarray) – 2D symmetric matrix.
eps (float) – Threshold for eigenvalues to be considered zero. Defaults to 1e-13.

Returns:

2D symmetric matrix, the square root of the input matrix.

Return type:

numpy.ndarray