pentapy.tools.create_banded
- pentapy.tools.create_banded(mat, up=2, low=2, col_wise=True, dtype=None)[source]
Create a banded matrix from a given quadratic Matrix.
The Matrix will to be returned as a flattend matrix. Either in a column-wise flattend form:
[[0 0 Dup2[2] ... Dup2[N-2] Dup2[N-1] Dup2[N] ] [0 Dup1[1] Dup1[2] ... Dup1[N-2] Dup1[N-1] Dup1[N] ] [Diag[0] Diag[1] Diag[2] ... Diag[N-2] Diag[N-1] Diag[N] ] [Dlow1[0] Dlow1[1] Dlow1[2] ... Dlow1[N-2] Dlow1[N-1] 0 ] [Dlow2[0] Dlow2[1] Dlow2[2] ... Dlow2[N-2] 0 0 ]]
Then use:
col_wise=True
Or in a row-wise flattend form:
[[Dup2[0] Dup2[1] Dup2[2] ... Dup2[N-2] 0 0 ] [Dup1[0] Dup1[1] Dup1[2] ... Dup1[N-2] Dup1[N-1] 0 ] [Diag[0] Diag[1] Diag[2] ... Diag[N-2] Diag[N-1] Diag[N] ] [0 Dlow1[1] Dlow1[2] ... Dlow1[N-2] Dlow1[N-1] Dlow1[N]] [0 0 Dlow2[2] ... Dlow2[N-2] Dlow2[N-2] Dlow2[N]]]
Then use:
col_wise=False
Dup1 and Dup2 or the first and second upper minor-diagonals and Dlow1 resp. Dlow2 are the lower ones. The number of upper and lower minor-diagonals can be altered.
- Parameters
mat (
numpy.ndarray
) – The full (n x n) Matrix.up (
int
) – The number of upper minor-diagonals. Default: 2low (
int
) – The number of lower minor-diagonals. Default: 2col_wise (
bool
, optional) – Use column-wise storage. If False, use row-wise storage. Default:True
- Returns
Bandend matrix
- Return type