Re: NNLS function

[Bill Denney]

On Wed, 8 Jun 2005, Dmitri A. Sergatskov wrote:

> Frank Palazzolo wrote:
>
> > However, I'm not sure if that's legal, since the comments say: "Adapted 
> > from NNLS of Mathworks, Inc.". (Unless you own Matlab?)
> >
> > That said, it is an optimized version of the algorithm which is 
> > supposedly faster and more flexible than the one in MATLAB.
> >
> > If it's not buried somewhere in octave already, the "right thing" is
>
> This would be a very bad thing to do actually. That would be a
> violation of Mathwork copyright. If one wants to write a nnls
> and contribute it to octave, she should not even look at
> this particular code, but rather get a book
>
> Lawson and Hanson, "Solving Least Squares Problems", Prentice-Hall, 
> 1974.
>
> (and perhaps those two references from readme.txt)
>
> and implement the algorithm from scratch.

It's a bit of a late follow-up, but the algorithm for NNLS is available 
from netlib at http://www.netlib.org/lawson-hanson/all, and there is a 
GPL'd C++ implementation at 
http://www.cs.utexas.edu/users/suvrit/work/progs/nnls.html .  So, a full 
re-implementation shouldn't be necessary.

I personally don't have the skill to do the implementation (well, I could 
possibly translate the fortran to octave, but I don't know how to 
interface fortran to octave or how to code C++).

Bill

--
"The main rule of writing is that, if you do it with enough assurance
and confidence, you're allowed to do whatever you like. (That may be a
rule for life as well as for writing. But it's definitely true for
writing.)"  -- Neil Gaiman



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