GAMS World Forum

Thanky for your answer, I tried different values (1,2,3,4,5) for mipstart in the option file cplex.opt but all (execpt mipstart=1) yield the following errors Reading parameter(s) from "C:\Users\wi9632\bwSyncAndShare\Graduiertenkolleg\Code\GAMS\Residential Area\cplex.opt" >> mipstart=5 *** ...

Thanks for your answer cladelpino, On the other hand, it is "easy" to see if a given solution is infeasible. Why don't you figure that out so that you're sure ? Basically it is not that easy to test if a solution is feasible because I have around 10000 binary decision variables and about 1...

Thanks for your answer "cladelpino ", I tried it and in the log there is the following information: Reading parameter(s) from "C:\Users\wi9632\GAMS\cplex.opt" >> mipstart=1 ... Reading data... Starting Cplex... Space for names approximately 2.77 Mb Use option 'names no' to turn u...

Thanks for the link. I know how parameters are exchanged between Excel and GAMS. For example if I want to load a price from a gdx file I have to write the following code: price(t) price $LOAD price" But now I do not want to load parameters, I want to transfer feasible solutions to the solver (C...

Hi guys, I want to use a starting solution for CPLEX. In the CPLEX manual of the GAMS webpage the following is written: "A MIP start will only be used by GAMS/CPLEX if the MipStart parameter is set to 1. The starting values must be set via the .L variable attribute in the GAMS model before the ...

Thanks Manassaldi for your answer, it seems to work, except for the very first two time slots. There the heating in stopped after 2 timeslots (which is not nice but not a big problem)

Hi guys, quite a long time ago I posted the question that you can see in the first post: I have a binary variable x(t) for every minute of a day (1440). This binary variable indicates if a heating device is on or off. Now I want to ensure that the device does not switch from on to off quite frequent...

Would anyone mind telling me whether my insereted code and the file are correct?

Thanks for your answer Fred, I inserted the following code in GAMS: mymodel.optfile = 1; then I created a file called cplex.opt and this file looks like this: * CPLEX options file mipemphasis 2 I changed the number but nothing seemed to have an effect on the results. I always get the same results (w...

Hi guys, sorry for not responding for so long. I was busy with other things. Now again the problem still remains that the computational time of my model has extremely increased altough I am not aware of any changes. I read about mipemphasis parameters: https://www.gams.com/latest/docs/S_CPLEX.html#C...