[SCIP] SCIP speed-up for .LP files

[Marcus Garvie]

Hi everyone,

this is my first post, so please understand that my knowledge of SCIP is low!

I have been solving some large binary linear programming problems with no objective function. I solve .LP files using a terminal to issue the commands on my Mac. The .LP files are automatically generated, with e.g. the attached format.

The only commands I issue are

SCIP> read test.lp
SCIP> optimize test.lp

The problem is that for very large problems (e.g. 28456 variables) the solver seems to be running forever (> 2 days)! I tried the same problem in Gurobi and it gave me the correct solution in 15 minutes. (I’m wanting to use SCIP because it has some easy options for giving me all feasible solutions, while Gurobi does not).

I also tried the problem in CPLEX, but it has some limitations on the length of the variable names (Error  1464) so I’m a little stuck if I want multiple solutions for large problems.

Any advice would be appreciated.

Marcus.

PS I only know how to problems in the  .LP format!



________________________________
Marcus R Garvie
Associate Professor
Rm 552 MacNaughton Bldg
Dept. of Math & Stats
University of Guelph
Guelph, ON Canada N1G 2W1
Tel. 519-824-4120 ext 53409
Email. mgarvie at uoguelph.ca<mailto:mgarvie at uoguelph.ca>



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