Re: [Help-glpk] Loading model files

[Noli Sicad]

Manish,

I am not really sure when you say GLPK in your post.  It seems that
you are referring to MathProg (GMPL) in GLPK/MathProg or you are
referring really to GLPK API C/C++ implementation of your model.

There are examples using GLPK API in C in calling MathProg (*.mod),
MPS (*.mps) in  glpk-4.42/examples folder. Have a look at the examples
with c extensions (*.c). The mplsamp2.c has function in calling
MathProg (*.mod) model  and data (*. dat). The sudoku.mod and
sudoku.dat which are the model and data being call in the c program.

It seems that you are referring to Knapsack problem (LP and DP),
(master and slave). Jeff Kantor webpage has DP converted in LP model.

Noli



On 2/17/10, Manish Jain <address@hidden> wrote:
> Hi all,
> I have my source code written in AMPL for Cplex, and I am currently porting
> it GLPK.
> The models don't work as is, since the original source code has some
> AMPL/CPlex specific commands.
> Besides, I am more comfortable writing scripts in C++ than with scripting in
> AMPL; however, I find that writing models in AMPL is easier.
>
> I have been able to convert most of my models to GLPK my adding rows,
> columns and generating the model row by row, column by column.
>
> I also saw in the manual that there is a function to load models and data
> files, however, I want to generate data on the fly i.e. I just want to load
> a model, and then
> generate data segments in the code. The requirement is such because I have a
> custom Branch and Price routine, and have two independent models for the
> 'master'
> and the 'slave'.
>
> Example model:
>
> param n;
> set N := {1..n};
> .
> .
> .
> var x {N} >= 0;
> .
> .
> .
> maximize objective: ...
> subject to:
> .
> .
> .
>
> What is the preferred way to do this, since I wasn't able to set the values
> of the parameters from the C++ code :|
>
>
> Manish Jain
> University of Southern California
>