scipy.linalg.lapack.sgbcon

scipy.linalg.lapack.sgbcon(kl, ku, ab, ipiv, anorm, norm='1', ldab=2 * kl + ku + 1) = <flapack function sgbcon>

Estimate the reciprocal condition number of a banded matrix from its gbtrf factorization (LAPACK sgbcon).

Parameters:

klint

Number of subdiagonals.

kuint

Number of superdiagonals.

abndarray

Band storage of shape (2 * kl + ku + 1, n): a[i, j] is held at ab[ku + i - j, j].

ipivndarray

Pivot indices from gbtrf, 0-based.

anormfloat

Norm of the original matrix, in the norm selected by norm.

normstr, optional

'1' or 'O' for the 1-norm, 'I' for the infinity norm. Default is '1'.

ldabint, optional

Leading dimension of ab, at least 2 * kl + ku + 1, which is also the default.

Returns:

rcondfloat

Estimate of the reciprocal condition number.

infoint

0 on success; if negative, the -info-th argument had an illegal value.