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

[Andrew Makhorin]

-------- Forwarded Message --------
From: Aly Megahed <address@hidden>
To: Robbie Morrison <address@hidden>, glpk xypron
<address@hidden>
Cc: GLPK help <address@hidden>
Subject: Re: [Help-glpk] [Fwd: No Memory Available Error]
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:

"data source name not found and no default driver specified".

I use a .dsn file to connect to the database, and that has been working
perfectly with the 32 bit GLPK. In that .dsn file, I have this written:

[ODBC]
DRIVER={Microsoft Excel Driver (*.xls)}
dbq=TestOne.xls

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

I understand Xypron's advice regarding switching my database to MySql. I
could potentially do this in the future, but for now, I really need to
connect to Excel and Access!

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?

Your help will be greatly appreciated!

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

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]