Search found 3 matches

by daniel93
5 years ago
Forum: Solvers
Topic: Impossible to use 'mipstart' in CPLEX
Replies: 1
Views: 4830

Impossible to use 'mipstart' in CPLEX

Hi, I have a trouble in using 'mipstart' in CPLEX. As far as I know, in order to activate mipstart, all the values of variables must be set with '.l' before solve statement. But when i do, it always return message 'MIP start 'm1' defined no solution' and 'Warning: No solution found from 1 MIP status...
by daniel93
5 years ago
Forum: Modeling
Topic: Using same identifier twice in variable.
Replies: 2
Views: 3982

Re: Using same identifier twice in variable.

thank you very much! I just learned the 'alias' function. It opens so many possibilities in formulation :) :)
by daniel93
5 years ago
Forum: Modeling
Topic: Using same identifier twice in variable.
Replies: 2
Views: 3982

Using same identifier twice in variable.

Hi. I'd like to implement model look like this.

Set
i

Variables
a(i)
b(i)
mult(i,i)

and mult(i1,i2) = a(i1) * a(i2) where i1, i2 are different or same elements of i.

How can i express this equation in GAMS?