Wednesday, June 11, 2008

GAMS/Xpress bug

It is not clear why GAMS/Xpress terminated here.

               S O L V E      S U M M A R Y

MODEL lp_model OBJECTIVE objvar
TYPE MIP DIRECTION MAXIMIZE
SOLVER XPRESS FROM LINE 53860

**** SOLVER STATUS 4 TERMINATED BY SOLVER
**** MODEL STATUS 9 INTERMEDIATE NON-INTEGER
**** OBJECTIVE VALUE 144.0000

RESOURCE USAGE, LIMIT 1612.694 10000.000
ITERATION COUNT, LIMIT 12233 10000000
Reading parameter(s) from "C:\projects\lpsolve\xpress.opt"
>> threads 4
>> cutstrategy 0
>> defaultalg 3
>> mippresolve 011
Finished reading from "C:\projects\lpsolve\xpress.opt"

Xpress-MP May 1, 2008 22.7.2 WIN 3906.4799 VIS x86/MS Windows
Xpress-MP licensed by Dash to GAMS Development Corp. for GAMS

The objective is a function of discrete variables only: jumpDist 1.
As a result, we set the MIP cutoff to 0.9995
Type of presolve applied: MIP presolve.
LP relaxation solved: objective = 144
Global search incomplete - no integer solution has been found



This may be a bug in the link instead of Xpress per se. Workaround: run again with default options will probably help.