Presolve Remove Duplicate Variables
Type: Selection
Range: The settings listed below
Default: On
This option controls whether the AIMMS Presolver should remove duplicate variables. If two variables in a mathematical program have the same coefficient in the objective function(s) and in each constraint, then one of the variables is redundant and can be removed. Possible values are:
On
Off
For example, suppose that the variables X and Y have the same coefficient in every row of the mathematical program and the bounds are as follows:
-∞ ≤ X ≤ ∞
0 ≤ Y ≤ ∞
In this case, it is possible to fix the variable Y = 0, and remove it.
Note
Only duplicate variables are removed for which both upper bounds (or both lower bounds) are infinite.
Only duplicate linear variables are removed.
This option has only an effect when solving a nonlinear model and the option Nonlinear Presolve is switched on, or when solving a linear, quadratic or quadratically-constrained model and the option Linear Presolve is switched on, or if the function GMP::Instance::CreatePresolved is used.
Learn more about