looking for nonnegative least squares solver

I am looking for a nonnegative least squares solver/toolbox. Anyone can point me to the right one?

Thanks

Answer 1

[madhan ravi]

See lsqnonneg

[Torsten]

Or for a nonlinear least squares problem: "lsqnonlin" together with the specification a of lower bound of 0 for the variables.

[madhan ravi]

Thank you @Torsten :)