[Help-glpk] Re: Hello,Nigel, I have some questions about GLPK

[Nigel Galloway]

I would of course reccomend users to be able to compile glpk themselves exactly 
as required, but to get started a binary version is a good introduction. Visual 
Basic 2008 is a .NET language and so works just like C# with a slightly 
different syntax. VB6 and other earlier versions of Visual Basic are dead 
languages.

To use glpk with C#, you probably want to build it with database support so 
using the Build_GLPK_with_VC9 with Makefile_VC6_MT_DLL is probably best:

rem Build GLPK with Microsoft Visual Studio Express 2008

rem NOTE: Make sure that HOME variable specifies correct path.
set HOME="C:\Program Files\Microsoft Visual Studio 9.0\VC"

call %HOME%\bin\vcvars32.bat
copy config_VC9 config.h
%HOME%\bin\nmake.exe /f Makefile_VC6_MT_DLL
%HOME%\bin\nmake.exe /f Makefile_VC6_MT_DLL check

Produces the following two files which are useful:

27/11/2008  20:23           913,408 glpk_4_33.dll
27/11/2008  20:23            36,864 glpsol.exe

C:\Users\Nigel\glpk-4.33>glpsol.exe --math huge.mod
Reading model section from huge.mod...
25 lines were read
Generating zumVariance...
Generating variances...
Model has been successfully generated
glp_simplex: original LP has 1048576 rows, 1048576 columns, 3145725 non-zeros
glp_simplex: presolved LP has 1048576 rows, 1048576 columns, 3145725 non-zeros
Scaling...
 A: min|aij| = 1.000e+000  max|aij| = 1.000e+000  ratio = 1.000e+000
Problem data seem to be well scaled
Crashing...
Size of triangular part = 1048575
      0: obj =  0.000000000e+000  infeas = 5.498e+011 (1)
*     1: obj =  0.000000000e+000  infeas = 0.000e+000 (0)
OPTIMAL SOLUTION FOUND
Time used:   64.6 secs
Memory used: 1694.9 Mb (1777205948 bytes)
The arithmetic mean of the integers from 1 to 1048575 is 524288.000000
Model has been successfully processed

Whilst the output has changed from previous versions it seems to work, and use 
less memory. I guess 'Crashing...' has a special glpk meaning and isn't as 
worrying as it is.

The real test is can we now compile examples\t1.cs

C:\Users\Nigel\glpk-4.33>csc /unsafe t1.cs
Microsoft (R) Visual C# 2008 Compiler version 3.5.21022.8
for Microsoft (R) .NET Framework version 3.5
Copyright (C) Microsoft Corporation. All rights reserved.

We can. What follows is probably not the Makefiles fault.

C:\Users\Nigel\glpk-4.33>t1 2424 772
a = 2424, b = 772
Hello Nigel
Trying 772
      0: obj =  0.000000000e+000  infeas = 1.000e+000 (0)
*     1: obj =  0.000000000e+000  infeas = 0.000e+000 (0)
OPTIMAL SOLUTION FOUND
Integer optimization begins...
+     1: mip =     not found yet >=              -inf        (1; 0)
Assertion failed: type != type
Error detected in file ..\src\glpios03.c at line 758
Assertion failed: lp->tree == NULL
Error detected in file ..\src\glpapi01.c at line 1365

The offending code is:

      /* determine new bounds of x[j] for down- and up-branches */

      new_ub = floor(beta);

      new_lb = ceil(beta);

      switch (type)

      {  case GLP_LO:

            xassert(lb <= new_ub);

            dn_type = (lb == new_ub ? GLP_FX : GLP_DB);

            xassert(lb + 1.0 <= new_lb);

            up_type = GLP_LO;

            break;

         case GLP_DB:

            xassert(lb <= new_ub && new_ub <= ub - 1.0);

            dn_type = (lb == new_ub ? GLP_FX : GLP_DB);

            xassert(lb + 1.0 <= new_lb && new_lb <= ub);

            up_type = (new_lb == ub ? GLP_FX : GLP_DB);

            break;

         default:

            /* other cases are not tested yet */

            xassert(type != type);

      }

This code was not exercised in 4.32 (compiled without db support).


> ----- Original Message -----
> From: "glpk xypron" <address@hidden>
> To: "Nigel Galloway" <address@hidden>, address@hidden
> Cc: address@hidden
> Subject: Re: Hello,Nigel, I have some questions about GLPK
> Date: Thu, 27 Nov 2008 14:19:16 +0100
> 
> 
> Hello Nigel,
> 
> I can add those files to http://winglpk.sourceforge.net
> 
> how should the dll be compiled?
> 
> Does the Build_GLPK_with_VC6_MT_DLL.bat produce a usable dll for 
> your purposes?
> Which calling convention should be used (standard call?)? At least 
> for Excel VBA standard call is needed. I do not know what .NET 
> needs.
> 
> Do you have any experience compiling the dll with Visual Studio Express 2008?
> Maybe a adapted makefile should be added to the distribution.
> 
> How about a 64bit dll? Currently there is not makefile for it.
> 
> Best regards
> 
> Xypron
> 
> 
> -------- Original-Nachricht --------
> > Datum: Thu, 27 Nov 2008 12:13:37 +0000
> > Von: "Nigel Galloway" <address@hidden>
> > An: "bo liu" <address@hidden>
> > CC: address@hidden, address@hidden
> > Betreff: Re: Hello,Nigel, I have some questions about GLPK
> 
> >  The tar.gz file is probably more suited to Unix. The zip file contains
> > glpsol.exe only which is enough if you just want to run examples written
> > in Mathprog. To be really useful as a Windows release the zip file should
> > contain a .Lib file which contains metadata about the glpk library.
> > glpsol.exe compiled against the .Lib file, which will be a lot smaller
> > than 800K. and a .dll file which is the shared library for Windows which
> > is needed for .Net applications.
> >
> >   ----- Original Message -----
> >   From: "bo liu"
> >   To: "Nigel Galloway"
> >   Subject: Re: Hello,Nigel, I have some questions about GLPK
> >   Date: Wed, 26 Nov 2008 21:36:44 +0800
> >
> >
> >     dear sir£¬
> >
> >   i'm sorry to borther you that i download glpk-4.33.tar.gz from this
> >   page
> >
> > http://sourceforge.net/project/showfiles.php?group_id=244007&package_id=297428&release_id=638021
> >   ,but i do not know how to install it. There is no exe files in it.I
> >   have read the glpk-4.33.pdf but i still don't know.My os is windows
> >   xp sp2.i want to use the glpk to solve LP problems.Should i have to
> >   download the glpsol-4.33.zip ?Hope you can help me . Best Wishes Bo
> >   Leo
> >
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