chemreac.util.banded

this module contains functions to deal with banded matrices.

chemreac.util.banded.get_banded(A, n, N, n_jac_diags=1, order='C', padded=False)

Turns a dense matrix into a banded one

Turns a dense matrix (n·N) × (n·N) into a banded matrix including the diagonal and n super-diagonals and n sub-diagonals.

Parameters

A: 2-dimensional square matrix

n: int

sub-block dimension

N: int

number of super-blocks

n_jac_diags: int

number of diagonals (default: 1)

order: {‘C’, ‘F’}, optional

C- or Fortran-contiguous

padded: bool, optional

default: False, if True: A is padded with n rows along the top

Raises

ValueError on mismatch of A.shape and n*N

chemreac.util.banded.get_jac_row_from_banded(J, rows, n, n_jac_diags=1)

Extracts rows from a banded matrix J

Parameters

J: 2-dimensional array

Source matrix with banded storage.

rows: sequence

indices of rows to extract

n: integer

row length

n_jac_diags: integer

number of diagonals (default: 1)