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[Help-glpk] Help Urgent
From: |
Andrew Makhorin |
Subject: |
[Help-glpk] Help Urgent |
Date: |
Fri, 1 Mar 2002 02:25:16 +0300 |
>I have been using GLPK/L, to solve a optimization problem with the number
>of variable between 100 and 300, that is a 100 X 100, 300 X 300 matrix.
>
>But when I use a number of variables bigger 100, the glpsol doesnot solve
>the problem. Then the following error is showed:
>
>load_model: reading model from `modeldesc1.lpm'...
>modeldesc1.lpm:11: too many columns
>glp_read_lpm1: processing terminated due to errors
>Model description processing error
>
>There is a limit of the number of columns that can be used in GLPK/L?
Yes, you reached a limit, because the glpk/l translator limits number of
columns in the table built-in function by 100. You may consider writing
your numeric material by using the data built-in function (i.e. in the
sparse format), which has no such limit.
NEVERTHELESS, you can enlarge this limit in the following way:
1. Be sure you have glpk-3.0.5.
2. Copy the file 'glplan5.c' into your working directory.
2. Replace the line 593, which looks like
#define MAX_COLS 100
by a line you need, for example:
#define MAX_COLS 500
3. Compile your program explicitly specifying the changed version of
'glplan5.c', i.e.
gcc main.c glplan5.c ... -lglpk ...
This limit was introduced quite arbitrarily, because it's difficult to
imagine a *full* table that has greater than 100 columns, isn't it :+)