GAMS — The Solver Manuals - Available Software

CPLEX 11 197
5 Sifting
6 Concurrent dual, barrier, and primal
quality (integer)
Write solution quality statistics to the listing file. If set to yes, the statistics appear after the Solve Summary
and before the Solution Listing.
(default = 0)
readflt (string)
The GAMS/Cplex solution pool options cover the basic use of diversity and range filters for producing
multiple solutions. If you need multiple filters, weights on diversity filters or other advanced uses of solution
pool filters, you could produce a Cplex filter file with your favorite editor or the GAMS Put Facility and
read this into GAMS/Cplex using this option.
reduce (integer)
Determines whether primal reductions, dual reductions, or both, are performed during preprocessing. It is
occasionally advisable to do only one or the other when diagnosing infeasible or unbounded models.
(default = 3)
reinv (integer)
0 No primal or dual reductions
1 Only primal reductions
2 Only dual reductions
3 Both primal and dual reductions
Refactorization Frequency. This option determines the number of iterations between refactorizations of the
basis matrix. The default should be optimal for most problems. Cplex’s performance is relatively insensitive
to changes in refactorization frequency. Only for extremely large, difficult problems should reducing the
number of iterations between refactorizations be considered. Any non-negative integer value is valid.
(default = 0, in which case it is determined automatically)
relaxfixedinfeas (integer)
Sometimes the solution of the fixed problem of a MIP does not solve to optimality due to small (dual)
infeasibilities. The default behavior of the GAMS/Cplex link is to return the primal solution values only.
If the option is set to 1, the small infeasibilities are ignored and a full solution including the dual values are
reported back to GAMS.
(default = 0)
0 Off
1 On
relaxpreind (integer)
This option will cause the Cplex presolve to be invoked for the initial relaxation of a mixed integer program
(according to the other presolve option settings). Sometimes, additional reductions can be made beyond
any MIP presolve reductions that may already have been done.
(default = -1)
-1 Automatic
0 do not presolve initial relaxation
1 use presolve on initial relaxation
relobjdif (real)
The relative version of the objdif option. Ignored if objdif is non-zero.
(default = 0)