Source code for Muscat.LinAlg.MatVecOperations

# -*- coding: utf-8 -*-
#
# This file is subject to the terms and conditions defined in
# file 'LICENSE.txt', which is part of this source code package.
#

import numpy as np


def ImmutableView(data: np.ndarray) -> np.ndarray:
    """Return a immutable view of a numpy array

    Parameters
    ----------
    data : np.ndarray
        input numpy array

    Returns
    -------
    np.ndarray
        immutable view of data
    """
    res = data.view()
    res.flags.writeable = False
    return res

# to eliminate dofs with know values


def DeleteRowsCols(A, rows, cols, fixedValues):
    """This function will be eliminated. Please do not use it

    Parameters
    ----------
    A : _type_
        _description_
    rows : _type_
        _description_
    cols : _type_
        _description_
    fixedValues : _type_
        _description_

    Returns
    -------
    _type_
        _description_
    """
    # Assumes that matrix is in symmetric csc form !

    rhs = A.dot(fixedValues)
    A = A[np.logical_not(rows), :]
    A = A[:, np.logical_not(cols)]

    return [A, rhs]


def CheckIntegrity():
    from scipy.sparse import csr_matrix

    fv = np.array([[1, 2],]).T
    mask = np.zeros(2)
    mask[1] = True
    for sp in [True, False]:
        if sp:
            K = csr_matrix([[1, 2], [3, 4]])
        else:
            K = np.array([[1, 2], [3, 4]])

        A, rhs = DeleteRowsCols(K, mask, mask, fv)
        print("using Sparse : " + ("True" if sp else "False"))
        print("Vals")
        print(A)
        print("--")
        print(rhs)
        print("Types")
        print(type(A))
        print(type(rhs))

    ImmutableView(np.array([4, 3, 2, 1]))
    return "ok"


if __name__ == '__main__':
    print(CheckIntegrity())  # pragma: no cover