Quantcast

Documentation Center

  • Trial Software
  • Product Updates

spalloc

Allocate space for sparse matrix

Syntax

S = spalloc(m,n,nzmax)

Description

S = spalloc(m,n,nzmax) creates an all zero sparse matrix S of size m-by-n with room to hold nzmax nonzeros. The matrix can then be generated column by column without requiring repeated storage allocation as the number of nonzeros grows.

spalloc(m,n,nzmax) is shorthand for

sparse([],[],[],m,n,nzmax)

Examples

To generate efficiently a sparse matrix that has an average of at most three nonzero elements per column

S = spalloc(n,n,3*n);
for j = 1:n
    S(:,j) = [zeros(n-3,1)' round(rand(3,1))']';end
Was this topic helpful?