MATLAB Function Reference    

Apply function to nonzero sparse matrix elements



The spfun function selectively applies a function to only the nonzero elements of a sparse matrix S, preserving the sparsity pattern of the original matrix (except for underflow or if fun returns zero for some nonzero elements of S).

f = spfun(fun,S) evaluates fun(S) on the nonzero elements of S. You can specify fun as a function handle or as an inline object.


Functions that operate element-by-element, like those in the elfun directory, are the most appropriate functions to use with spfun.


Given the 4-by-4 sparse diagonal matrix

Because fun returns nonzero values for all nonzero element of S, f = spfun(@exp,S) has the same sparsity pattern as S.

whereas exp(S) has 1s where S has 0s.

See Also

function handle (@), inline

  speye sph2cart