scipy.linalg.lapack.dlansb

scipy.linalg.lapack.dlansb(k, ab, norm='1', uplo='U', ldab=k + 1) = <flapack function dlansb>

Compute a norm of a symmetric band matrix (LAPACK dlansb).

For the complex flavors the matrix is complex symmetric, not Hermitian.

Parameters:

kint

Number of super-diagonals (uplo='U') or sub-diagonals (uplo='L').

abndarray, shape (ldab, n)

The upper or lower triangle of the matrix in symmetric banded storage, k + 1 rows.

normstr, optional

'M' for the largest absolute value, '1' or 'O' for the 1-norm, 'I' for the infinity norm, 'F' or 'E' for the Frobenius norm. Lower case is accepted. Note that 'M' is not a consistent matrix norm. Default is '1'.

uplostr, optional

Whether ab stores the upper ('U', default) or lower ('L') triangle.

ldabint, optional

Leading dimension of ab, at least k + 1, which is also the default.

Returns:

n2float

The requested norm, always real.