Technical Item! was: Re: [Coin-standards] Re: SMPS reader

[Leonardo B. Lopes]

Good. So why don't we start with the following question:

What is the best sparse matrix representation to use? The candidates that
come to mind to me are:

- The MPS style matrix: i,j, A_ij

- Compressed Row or Compressed Column. I use CC.

- Diagonal Band

- Compressed Diagonal

- Block Storage plus one of the above

Remembering of course that we won't be performing inner products or
gaussian-type operations on these, but instead a lot of set unions and
intersections (at least in SMPS). In addition, one of these will actually
be returned to someone writing a solver or something similar. I haven't
seen John Forrets' MPS reader. What does he use?

Cheers,
Leo.

On Mon, 15 Apr 2002, Gus Gassmann wrote:

> Hi guys,
> 
> I have kept up my reading of your submissions, but I was a bit 
> susrprised at the heavy traffic, hence have not been able to keep 
> up with the writing.
> 
> > John Forrest has just contributed an open source MPS file reader to
> > the OSI package on COIN.  I would like to do the same for a Stochastic
> > MPS file reader. (Of course, there is a working SMPS reader in OSLSE. 
> > But this connects to the structures of the OSLSE package, which are
> > byzantine, to say the least.)
> > 
> > I think you should be interested in this, because if your modeling
> > standard supports stochastic programming it certainly should be able
> > to implement SMPS.  It would be a good test case for your proposals.
> > 
> > Now, to be truly open source there has to be a community.  So, are you
> > (or anyone out there) interested in developing an open source SMPS
> > file reader? If so, write me a note and lets get started.
> 
> Yes, chalk up one keen expression of interest from me. Of course 
> MSLiP has its own reader, in fact implementing many if not all of 
> the features of the extended SMPS, but as Alan's it connects to 
> the internal structures of MSLiP, which are equally hoary and 
> patched up.
> 
> 
> 
> -------------------------------------------------------
> 
> gus gassmann          (Horand.Gassmann at dal.ca)
> 
> School of Business Administration, Dalhousie University
> Halifax, Nova Scotia, Canada , B3H 1Z5
> ph. (902) 494-1844
> fax (902) 494-1107
> 
> http://www.mgmt.dal.ca/sba/profs/hgassmann/
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========================================================================
Leonardo B. Lopes                                       leo at iems.nwu.edu 
Ph.D. Student                                              (847)491-8470
IEMS - Northwestern University              http://www.iems.nwu.edu/~leo