Re: Matrix regression of distance matrices + non negative least square

[Corrado]

Dear Jaroslav,

by the way, 

lsqnonneg

is not among the packages I can install on my octave. I know there is a 
lsqnonneg package in Matlab.

Regard

On Monday 07 September 2009 14:39:04 Jaroslav Hajek wrote:
> On Mon, Sep 7, 2009 at 2:38 PM, Corrado<address@hidden> wrote:
> > Dear friends,
> >
> > I would like to solve the following regression problem:
> >
> > y=c1 x1 + c2 x2 + .... + cn xn
> >
> > where the y, xi are all matrices and the ci are constants that need to be
> > determined. The y, xi are distance matrices (symmetric). Obviously ci
> > should be forced to positive or null (i.e. non negative).
> >
> > Any suggestion?
>
> First convert the linear system into canonical form (matrix of
> coefficients and vector of rhs), then use lsqnonneg.
> Since the matrices are symmetric, extracting just lower/upper
> triangular parts will suffice. The best way how to do the first will
> depend on the dimensionality of your problem and how your data is
> stored.
>
> regards



-- 
Corrado Topi

Global Climate Change & Biodiversity Indicators
Area 18,Department of Biology
University of York, York, YO10 5YW, UK
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