sparse — sparse matrix definition
sp=sparse(X) sp=sparse(ij,v [,mn])
real or complex full (or sparse) matrix
two columns integer matrix (indices of non-zeros entries)
vector
integer vector with two entries (row-dimension, column-dimension)
sparse matrix
sparse
is used to build a sparse matrix. Only non-zero entries
are stored.
sp = sparse(X)
converts a full matrix to sparse form by
squeezing out any zero elements. (If X
is already sparse
sp
is X
).
sp=sparse(ij,v [,mn])
builds an mn(1)
-by-mn(2)
sparse matrix with sp(ij(k,1),ij(k,2))=v(k)
.
ij
and v
must have the same column dimension.
If optional mn
parameter is not given the sp
matrix dimensions are the max value of ij(:,1)
and ij(:,2)
respectively.
Operations (concatenation, addition, etc,) with sparse matrices are made using the same syntax as for full matrices.
Elementary functions are also available (abs,maxi,sum,diag,...
)
for sparse matrices.
Mixed operations (full-sparse) are allowed. Results are full or sparse depending on the operations.