C Name

CPX_PARAM_BTTOL

C++ Name

BtTol

Java Name

BtTol

.NET Name

BtTol

InteractiveOptimizer

mip strategy backtrack

Identifier

2002

Description

Controls how often backtracking is done during the branching process. The decision when to backtrack depends on three values that change during the course of the optimization:

The target gap is defined to be the absolute value of the difference between the incumbent and the best node, multiplied by this backtracking parameter. CPLEX does not backtrack until the absolute value of the difference between the objective of the current node and the best node is at least as large as the target gap.

Low values of this backtracking parameter thus tend to increase the amount of backtracking, which makes the search process more of a pure best-bound search. Higher parameter values tend to decrease backtracking, making the search more of a pure depth-first search.

The backtracking value has effect only after an integer feasible solution is found or when a cutoff has been specified. Note that this backtracking value merely permits backtracking but does not force it; CPLEX may choose to continue searching a limb of the tree if that limb seems a promising candidate for finding an integer feasible solution.

Values

Any number from 0.0 to 1.0; default: 0.9999

See Also