|
From: | Hernandez Florent |
Subject: | [Help-glpk] memory problem solving a 4221 var and 1336 constraints |
Date: | Wed, 1 Oct 2008 20:50:43 +0400 |
memory problem solving a 4221 var and 1336 constraintsI have a memory problem solving a simplex (real variables) with 4221 var and 1336 inequality constraints The file written by glpk routine glp_write_lp() amounts to 140 MBytes. When I read this file and try to solve it, memory usage climbs up to 1.5 Gbytes. Then the malloc death sentence falls "umalloc: size = 8016; malloc failed ". Why does my problem need so much RAM within glpk ? I would expect far less. When glpk reads the file, it says it has 1336 rows (correct), 8 910 531 columns (why?) and 1 312 263 non zero values in the matrix. Any help ? Is it possible to handle glpk so that it minimises memory usage ? Or should I think about another solver (which I don't want to!) thanks, Florent HERNANDEZ
I have a memory problem solving a simplex (real variables) with 4221 var and 1336 inequality constraints
The file written by glpk routine glp_write_lp() amounts to 140 MBytes.
When I read this file and try to solve it, memory usage climbs up to 1.5 Gbytes.
Then the malloc death sentence falls "umalloc: size = 8016; malloc failed ".
Why does my problem need so much RAM within glpk ?
I would expect far less.
When glpk reads the file, it says it has 1336 rows (correct), 8 910 531 columns (why?)
and 1 312 263 non zero values in the matrix.
Any help ?
Is it possible to handle glpk so that it minimises memory usage ?
Or should I think about another solver (which I don't want to!)
thanks,
Florent HERNANDEZ
[Prev in Thread] | Current Thread | [Next in Thread] |