Re: [Help-glpk] Import data from Matlab variables to GLPK/GMPL

[Reginald Beardsley]

Nazmul,

I suggest you consider using  awk to generate data files in GMPL format from 
ASCII text (.txt) files if you have very many instances to solve.  You put the 
problem formulation in one file and the data for each instance in  another file 
and execute "gplsol -m model.dat -d data.dat".  I've found this works very well 
solving large numbers of problem instances.  In particular, it makes changing 
the model very simple.  I can't find out anything about the Guesk editor so I 
can't comment on setting up GMPL notation data files using that.

I tried using the CSV import facility in GMPL, but found it not very convenient 
because of restrictions on the CSV format glpk accepts.  

There is a MATLAB binding for GLPK, but I don't know how usable it is.  The 
MATLAB clone, Octave, also has a built-in binding to GLPK.

http://en.wikibooks.org/wiki/GLPK/Matlab

http://en.wikibooks.org/wiki/GLPK/Octave

http://en.wikibooks.org/wiki/GLPK/Scripting_plus_MathProg

There is a Gnu implementation of awk, gawk, which is standard on Linux systems. 
 It's also available on Windows.

http://gnuwin32.sourceforge.net/packages/gawk.htm

If you need help with writing an awk script to convert the MATLAB .txt files to 
GMPL notation send me a small example of the MATLAB .txt file and I'll add an 
example to the GLPK wiki.

You'll need to figure out how to write a basic GMPL problem first.  A good 
place to look is in the examples directory at cf12a.mod which implements an L1 
line fit.  I solve physics inverse  problems by basis pursuit using GMPL 
notation so I can probably offer some help.  I do problems with 30,000 columns 
by 50-300 rows.  The resulting files are huge, so you want to get everything 
working using a small example before doing something that large.  I did some 
little 10x10 problems to figure out how to set it up.

Reg




--------------------------------------------
On Thu, 12/26/13, Nazmul Islam <address@hidden> wrote:

 Subject: [Help-glpk] Import data from Matlab variables to GLPK/GMPL
 To: address@hidden
 Date: Thursday, December 26, 2013, 8:49 PM
 
 Hello,
 I want to write my GLPK code through the Guesk
 editor and I am very new to the GNU Math Programming
 Language. 
 I want to import some data from Matlab to my GLPK
 code. I want to run the code with these imported data. The
 data is currently in some variables of Matlab and I can
 store them in some .mat files. Do I need to save all these
 Matlab variables in a single .dat file (or .txt file?) and
 then import to GNU Math Prog language?
 
 Is there any example that I can
 follow?
 Thanks,
 Nazmul
 
 
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