GAMS World Forum

Hi, Mentioned GAMS error is common and self-explanatory. For example, unkown symbol - states that symbol is not defined. find the symbol and define it or check for typo error if you think it is already defined. Use GAMS manual for removing the error. As you have not posted complete GAMS code, it is ...

Renger Sir,

Thank you.

Hello Everyone, I am trying to solve a problem which has two levels. Decision variables in both levels are interacting with each other i.e. decision variable of one level is treated as a parameter for other level and vice-versa. I am solving it individually and feeding output of one level to others....

Hello All, I am trying to change default value of MIP Algorithmic Options such as preslvnd from 0 to -1. I am not sure how to make such changes. I am enclosing more info on this option. Kindly help... preslvnd (integer): node presolve selector Indicates whether node presolve should be performed at t...

In CPLEX, preslvnd (integer): node presolve selector has default value = 0.
I want to change its value to -1.
Can anybody help me what would be the syntax for it or what setting should be done??

Thank You.

Hi,

Hope your problem is solved. anyway here is the solution to your problem.

This error comes when (any) input parameter is not provided.
Just check all the input parameter is provided. You can use display command.

How to simulate bi-level model using emp in GAMS? when variable x depends upon variable y in the upper level and variable y depend on x in the lower level problem? For example Upper level Min x-4y (minimize x) s.t. 2x-3y>=0, Lower Level Min y s.t. x+y>=3 2x-y>=0 -2x-2y>=12 -3x+2y>=-4 How it can be s...