spalloc

Allocate space for an m × n sparse matrix.

Syntax

S = spalloc(m, n, nzmax)

Description

Returns an empty m × n sparse matrix with storage pre-allocated for nzmax non-zero entries. Doesn’t insert any values — a placeholder for a sparse matrix you’ll fill incrementally without triggering reallocations on each assignment.

Examples

S = spalloc(1000, 1000, 50);   % allocate for up to 50 nonzeros
for i = 1:50
    S(i, i) = i;
end

See also

• sparse — Create a sparse matrix.
• nnz — Number of non-zero elements.
• nzmax — Storage allocated for non-zero elements.