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bundles / scipy 1.17.1 / scipy / sparse / linalg / _matfuncs / _onenormest_product

function

scipy.sparse.linalg._matfuncs:_onenormest_product

source: /scipy/sparse/linalg/_matfuncs.py :295

Signature

def   _onenormest_product ( operator_seq t = 2 itmax = 5 compute_v = False compute_w = False structure = None )

Summary

Efficiently estimate the 1-norm of the matrix product of the args.

Parameters

operator_seq : linear operator sequence

Matrices whose 1-norm of product is to be computed.

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.

structure : str, optional

A string describing the structure of all operators. Only upper_triangular is currently supported.

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_product