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[Help-glpk] need help to understand why glpk cant solve my problem
From: |
olf |
Subject: |
[Help-glpk] need help to understand why glpk cant solve my problem |
Date: |
Tue, 5 Dec 2006 12:09:34 +0300 |
First of all I would just like to say hello too you all and I hope I wont
make a complete fool out of myself for writing this :)
I am trying to solve a train dispatching problem.
I have a graph with 54 nodes and I want two trains to travel from
different starting nodes and switch places. So basically I want train a to
go from node i to node j and I want train b to go from node j to node i.
I have set up a simple mathematical model to avoid collisions between the
trains.
The error message I get from running this is the following:
spx_invert: the basis matrix is singular
spx_simplex: numerical problems with basis matrix
spx_simplex: sorry, basis recovery not implemented yet
mip_driver: cannot solve current LP relaxation
lpx_integer: cannot solve current LP relaxation
Now this is a fairly big problem and I am not sure glpk can solve it at all.
So I am mostly trying to understand _why_ it cant solve it.
My guess is that it just is to big, but I wanted to make sure that that is
the case and I hope maybe one of you could confirm it or explain it to me.
If you want the acctual data and model files just say so and I will supply
them.
Best regards
/Olle Claeson
- [Help-glpk] need help to understand why glpk cant solve my problem,
olf <=