Originally posted by: SystemAdmin

[susana_sze said:]

Hi,

I'm trying to solve a problem similar to cutstock with column generation.
I have x_i_j as my dvar in the problem

Due to the large problem size, I use some some heuristic/logical rule to find some value of x_i_j which is known as zero before hand at dot net.  I want to fix those x_i_j equals to zero directly into the mod file as dvar. Is that possible to do so? If yes, how to fix those dvar?

Thanks in advance.

Susana
#DecisionOptimization
#OPLusingCPLEXOptimizer

Originally posted by: SystemAdmin

[jfk said:]

Hello,
in this example:

ILOG OPL Development Studio 6.1.1 > Language > Language User’s Manual > ILOG Script for OPL > Tutorial: Flow control and multiple searches > Doing more with mulprod_main > Modifying the CPLEX matrix incrementally

you can see how you can change the upper bound of a variable. You can do the same for lower bound. So if you fix the lower+upper bound to the same value then you ultimately fix the variable.


I hope it helps

cheers
#DecisionOptimization
#OPLusingCPLEXOptimizer

Originally posted by: SystemAdmin

[susana_sze said:]

Thanks for the information.

but does it possible to do it for decision variable as well?
I define the decision variable as boolean

Thanks
Susana
#DecisionOptimization
#OPLusingCPLEXOptimizer

Originally posted by: SystemAdmin

[jfk said:]

Hello,
I can see API for setUB, setLB and setBounds for setting lower/upped/bounds on variables.


cheers
#DecisionOptimization
#OPLusingCPLEXOptimizer