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bundles / scipy 1.18.0 / scipy / sparse / linalg / _matfuncs / _onenormest_matrix_power

function

scipy.sparse.linalg._matfuncs:_onenormest_matrix_power

source: /scipy/sparse/linalg/_matfuncs.py:253

Signature

def _onenormest_matrix_power(A, p, t = 2, itmax = 5, compute_v = False, compute_w = False, structure = None)

Summary

Efficiently estimate the 1-norm of A^p.

Parameters

A : ndarray

Matrix whose 1-norm of a power is to be computed.

p : int

Non-negative integer power.

t : int, optional

A positive parameter controlling the tradeoff between accuracy versus time and memory usage. Larger values take longer and use more memory but give more accurate output.

itmax : int, optional

Use at most this many iterations.

compute_v : bool, optional

Request a norm-maximizing linear operator input vector if True.

compute_w : bool, optional

Request a norm-maximizing linear operator output vector if True.

Returns

est : float

An underestimate of the 1-norm of the sparse arrays.

v : ndarray, optional

The vector such that ||Av||_1 == est*||v||_1. It can be thought of as an input to the linear operator that gives an output with particularly large norm.

w : ndarray, optional

The vector Av which has relatively large 1-norm. It can be thought of as an output of the linear operator that is relatively large in norm compared to the input.

Aliases

  • scipy.sparse.linalg._matfuncs._onenormest_matrix_power