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| spalloc | Examples |
Allocate space for sparse matrix
S = spalloc(m,n,nzmax)
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)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