GAMS — The Solver Manuals - Available Software

CPLEX 11 199
rinsheur (integer)
Cplex implements a heuristic known a Relaxation Induced Neighborhood Search (RINS) for MIP and
MIQCP problems. RINS explores a neighborhood of the current incumbent to try to find a new, improved
incumbent. It formulates the neighborhood exploration as a MIP, a subproblem known as the subMIP, and
truncates the subMIP solution by limiting the number of nodes explored in the search tree.
Parameter rinsheur controls how often RINS is invoked. A value of 100, for example, means that RINS is
invoked every hundredth node in the tree.
(default = 0)
-1 Disable RINS
0 Automatic
rngrestart (string)
Write ranging information, in GAMS readable format, to the file named. Options objrng and rhsrng are
used to specify which GAMS variables or equations are included.
(default = ranging information is printed to the listing file)
scaind (integer)
This option influences the scaling of the problem matrix.
(default = 0)
-1 No scaling
0 Standard scaling. An equilibration scaling method is implemented which is generally very effective.
1 Modified, more aggressive scaling method. This method can produce improvements on some problems.
This scaling should be used if the problem is observed to have difficulty staying feasible during the
solution process.
siftalg (integer)
Sets the algorithm to be used for solving sifting subproblems.
(default = 0)
0 Automatic
1 Primal simplex
2 Dual simplex
3 Network simplex
4 Barrier
siftdisplay (integer)
Determines the amount of sifting progress information to be displayed.
(default = 1)
0 No display
1 Display major iterations
2 Display LP subproblem information
siftitlim (integer)
Sets the maximum number of sifting iterations that may be performed if convergence to optimality has not
been reached.
(default = large)