sparse edit page
SPARSE Create sparse matrix.
S = SPARSE(X) converts a sparse or full matrix to sparse form by squeezing
out any zero elements.
S = sparse(i,j,s,m,n,nzmax) uses vectors i, j, and s to generate an
m-by-n sparse matrix such that S(i(k),j(k)) = s(k), with space
allocated for nzmax nonzeros.  Vectors i, j, and s are all the same
length.  Any elements of s that are zero are ignored, along with the
corresponding values of i and j.  Any elements of s that have duplicate
values of i and j are added together.  The argument s and one of the
arguments i or j may be scalars, in which case the scalars are expanded
so that the first three arguments all have the same length.
S = SPARSE(i,j,s,m,n) where nzmax = length(s).
S = SPARSE(i,j,s) where m = max(i) and n = max(j).
S = SPARSE(m,n) abbreviates SPARSE([],[],[],m,n,0).  This
generates the ultimate sparse matrix, an m-by-n all zero matrix.
For example, this dissects and then reassembles a sparse matrix:
            [i,j,s] = find(S);
            [m,n] = size(S);
            S = sparse(i,j,s,m,n);
So does this, if the last row and column have nonzero entries:
            [i,j,s] = find(S);
            S = sparse(i,j,s);
All of MATLAB's built-in arithmetic, logical and indexing operations
can be applied to sparse matrices, or to mixtures of sparse and
full matrices.  Operations on sparse matrices return sparse matrices
and operations on full matrices return full matrices.  In most cases,
operations on mixtures of sparse and full matrices return full
matrices.  The exceptions include situations where the result of
a mixed operation is structurally sparse, eg.  A .* S is at least
as sparse as S.


v = sparse(i,j,v,varargin)

See also