Re: MathProg, glpk and C language

In addition to my previous explanatory mail, please allow to redirect you
to the following link:
https://www-01.ibm.com/software/commerce/optimization/interfaces/
There it is mentioned that : "Component Libraries include two interfaces,
ILOG Concert Technology and CPLEX Callable Library.* C*, C++, C#, Java,
Visual Basic, python and FORTRAN developers *can embed powerful CPLEX
algorithms and OPL models within their application programs*.".
I want to implement somthing like this, but instead of using OPL, I want to
use MathProg, i.e. to embed an MathProg model inside the C function. Then
the function will be responsible for providing the main C program with the
results of the solved MIP problem.

2017-10-04 14:10 GMT+03:00 john tass <[email protected]>:

> Hi Lyndon,
> First of all I would like to thank you for your concern.
> As a matter of fact, the case you mention is not my case. I have a C
> program with several functions (written in pure C) . But I want to write
> one function (I do not know the syntax of its programming code), which is
> intended to solve an MIP problem and return the results (solution of MIP)
> to the main C program which calls this function. I do not want to leave the
> C environment at all.
> One possible way I suppose that is to use the API's of Glpk inside that
> function, using #include "glpk.h". But this way has the following
> drawback: in order to declare a structural variable of my model, say X1, I
> have to write something like glp_set_col_name(lp, 1, "x1"); That means
> that I declare the X1 variable by a hard-code. But my model is quite large,
> having hundreds of variables. In addition, I do not know in advance the
> exact number of them since they should be created dynamically. As you
> understand it is impossible to repeat the above declaration for some
> hundreds of times, to say nothing about the writing of the constraints.
> Please bear in mind that I do not want to exit the C environment, nor to
> create the model by C in a text file, then read the mod file, solve the
> problem via glpk and write the results in a text file, from where the C
> would read them.
> So it cross my mind the idea of using MathProg, since it is a modelling
> language which provides the user with an easy way to represent the models.
> I repeat: I do not want to create a .mod file in MathProg and feed it to
> glpsol. I want to use MathProg inside a C function.
> I hope that I have been understood now. I apologize if I was previously
> not clear enough.
> Thanks for your help.
>
> 2017-10-04 11:25 GMT+03:00 Lyndon D'Arcy <[email protected]>:
>
>> Hi John,
>>
>> If I understand correctly, you would like to programmatically generate
>> some MathProg code inside of your C program, and then read that generated
>> code with the GLPK API?
>>
>> Cheers,
>> Lyndon
>>
>> On Wed, 4 Oct 2017 at 4:23 am, john tass <[email protected]> wrote:
>>
>>> Good evening.
>>> I am trying to write a function in ANCI C programming language. The aim
>>> of this function is to get some input arguments from the main C program,
>>> then solve a MIP problem and return the value of objective function
>>> along with the values of structural variables back to the C main program.
>>> The issue is that the MIP problem I am about to solve via glpk has a
>>> quite large number of variables. So, I am not able to hard-code them.
>>> Hence, I came across the idea to use MathProg language, as it is very
>>> easy to code my model.
>>> The question is, how to do this? Is it possible to incorporate MathProg
>>> code inside a C language function? Please note that I am aware of how to
>>> write a C program that calls API routines of glpk in order to solve a
>>> simple model, but here I am not referring to this case.
>>> Any suggestion of a site, pdf or relevant document will be very helpful.
>>> Thanks in advance to any one who is willing to help me.
>>>
>>> --
>>> Dr. Ioannis X. Tassopoulos, MSc., Ph.D.
>>>
>>> _______________________________________________
>>> Help-glpk mailing list
>>> [email protected]
>>> https://lists.gnu.org/mailman/listinfo/help-glpk
>>>
>>
>
>
> --
> Dr. Ioannis X. Tassopoulos, MSc., Ph.D.
>
>


-- 
Dr. Ioannis X. Tassopoulos, MSc., Ph.D.

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