Re: [Help-glpk] [Fwd: No Memory Available Error]

[Robbie Morrison]

Hi Aly

------------------------------------------------------------
To:           Robbie Morrison <address@hidden>, glpk xypron
<address@hidden>
Subject:      Re: [Help-glpk] [Fwd: No Memory Available Error]
Message-ID: 
<address@hidden>
From:         Aly Megahed <address@hidden>
Date:         Sat, 18 Aug 2012 08:31:16 -0400 (EDT)
------------------------------------------------------------

> Thanks a lot for your replies, Robbie and
> Xypron. I did understand your excellent remarks,
> but I still do have a couple of questions, please:
>
> 1. So, I tried to use the 64 bit GLPK on a machine
> with windows 7 64 bit and Excel and Access 64
> bit. However, when connecting to the Excel or the
> access database through ODBC, I get the following
> error:

[snip : ODBC error messages and configurations]

> Any thoughts why this is not working, and how can
> I get it to work?

I don't use these tools, but have you looked here:

  http://en.wikibooks.org/wiki/GLPK/ODBC
  http://en.wikibooks.org/wiki/GLPK/Windows_IDEs#Microsoft_Excel_integration

[snip : migrating to MySql]

> 2. I used to use CPLEX through generating the .lp
> or the .mps file through GLPK, then solve that
> using CPLEX. However, I was wondering if there is
> a way to automatically call CPLEX within the GLPK
> code (which would enable me to get the solutions
> from CPLEX back, and play with them,....etc). I
> saw in one of the links that Robbie sent, a C code
> that apparently does this. Is there any other
> direct easier way to do that?

I'm not sure about system calls from within
MathProg (but someone will).  But you could
perhaps do it the other way around, call GLPSOL
from a script.  Any scripting language would do
(bash, perl, python, ruby) or whatever is native
on Windows box.

In which case, have you looked here:

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

The other option is to program more directly, also
using a scripting language.  For example, python:

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

> Your help will be greatly appreciated!

good luck with your project!  Robbie

> Best,
> Aly
>
> ----- Original Message -----
> From: "Robbie Morrison" <address@hidden>
> To: "GLPK help" <address@hidden>
> Cc: "Aly Megahed" <address@hidden>
> Sent: Wednesday, August 15, 2012 6:49:23 PM
> Subject: Re: [Help-glpk] [Fwd: No Memory Available Error]
>
> Hi Aly

[snip]

Are you signed on to this list?  If not:

  http://lists.gnu.org/mailman/listinfo/help-glpk

------------------------------------------------------------
To:           glpk xypron <address@hidden>
Subject:      No Memory Available Error
From:         Aly Megahed <address@hidden>
Date:         Wed, 15 Aug 2012 09:58:24 -0400 (EDT)
------------------------------------------------------------

> I am using glpk 32 bit on a 64 bit windows 7 machine,
> and I use a 32 bit Excel.

Why not upgrade to 64-bit Excel?  (Your email address
suggests Georgia Tech?)

> 2. Is there any way I can call CPLEX or Gurobi as the
> solver for the models I generate on GLPK?

You can use GLPSOL to generate the problem in CPLEX LP
format and then feed that to another solver:

    http://en.wikibooks.org/wiki/GLPK/Interoperability
    http://en.wikibooks.org/wiki/GLPK/Interoperability#GLPSOL_usage
    http://en.wikibooks.org/wiki/GLPK/Interoperability#CPLEX.C2.A0LP_format

The call is:

    $ glpsol --check --wlp model.lp --math model.mod

GLPK can also tackle the same file:

   $ glpsol --lp model.lp

If you encounter problems, you could also try bridging
with the MPS free format.  Described in the above links.

You might also find something useful here, particularly
if you are coding in C, Java, or similar:

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

HTH, Robbie
---
Robbie Morrison
PhD student -- policy-oriented energy system simulation
Technical University of Berlin (TU-Berlin), Germany
University email (redirected) : address@hidden
Webmail (preferred)           : address@hidden
[from Webmail client]