MATLAB Functions Help Desk

nzmax

Purpose

Amount of storage allocated for nonzero matrix elements

Syntax

Description

n = nzmax(S) returns the amount of storage allocated for nonzero elements.

If S is a sparse matrix...

nzmax(S) is the number of storage locations allocated for the nonzero elements in S.

If S is a full matrix...

nzmax(S) = prod(size(S)).

Often, nnz(S) and nzmax(S) are the same. But if S is created by an operation which produces fill-in matrix elements, such as sparse matrix multiplication or sparse LU factorization, more storage may be allocated than is actually required, and nzmax(S) reflects this. Alternatively, sparse(i,j,s,m,n,nzmax) or its simpler form, spalloc(m,n,nzmax), can set nzmax in anticipation of later fill-in.

See Also

find        Find indices and values of nonzero elements

nnz         Number of nonzero matrix elements

nonzeros    Nonzero matrix elements

size        Array dimensions

whos        List directory of variables in memory

isa         Detect an object of a given class


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