bundles / scipy 2.0.0.dev0+git20260907.41eeb59 / scipy / sparse / linalg / _funm_multiply_krylov / _funm_multiply_krylov_lanczos

function

`scipy.sparse.linalg._funm_multiply_krylov:_funm_multiply_krylov_lanczos`

source: build-install/usr/lib/python3.14/site-packages/scipy/sparse/linalg/_funm_multiply_krylov.py:95

Signature

def _funm_multiply_krylov_lanczos(A, b, bnorm, V, H, m)

Summary

The Lanczos iteration for constructing the basis V and the projection H = V * A V for the Krylov subspace Km(A, b) of order m. A must be Hermitian.

Parameters

A : transposable linear operator: The operator whose matrix function is of interest.
b : ndarray: The vector b to multiply the f(A) with.
V : ndarray: The n x (m + 1) matrix whose columns determines the basis for Krylov subspace Km(A, b).
H : ndarray: A (m + 1) x m upper Hessenberg matrix representing the projection of A onto Km(A, b).
m : int: The order of the Krylov subspace.

Returns

breakdown : bool: Indicate if the Arnoldi broke down or not
iter : int: Returns the last valid iteration.

Aliases

scipy.sparse.linalg._funm_multiply_krylov._funm_multiply_krylov_lanczos