GAMS World Forum

Looks correct. Please share your gms and log file. Fixing a problem with partial information is difficult.

Fred

I doubt that you will find help this way. Your chances to get help will be much better if you follow the forum rules.

Fred

Hi Simon, Half an hour model generation time for a model of that size is indeed incredibly long. Hard to say why it takes so long without being able to reproduce. Here we have some hints on how to implement models efficiently. If you could share the model/data, it might be easier for other forum use...

Hi, The McCarl Newsletter Volume 47 has a good introduction to model scaling and also gives some pointers to other places (like the GAMS documentation) where model scaling is discussed: https://www.gams.com/newsletter/mccarl/archive/mccarl_newsletter_no_47.pdf There are diffreent ways to detect wher...

Hi,

The error message actually says it all: You declare equation k888 in line 2571 but you never define it.

I hope this helps!

Fred

Hi,

You have to end the definition of each equation with a semicolon.

Best,
Fred

Hi, Running with default settings (see Corre_iny_CON_Perdidas_baseline.log), the root relaxation already takes already 334 seconds on my machine. Afterwards, Cplex spends ages with the generation of flow cover cuts (I killed the job after half an hour). With that said, I tried to run the model with ...

Hi, Why do you want to solve the fixed MIP as an LP? If this is about the duals you would like to get for that fixed MIP, many solver links (e.g. GAMS/CPLEX) have a built-in option to solve the LP which you would get when fixing all discrete variables. For GAMS Cplex, this can be controlled via solv...

Hi,

hard to help without beiong able to reproduce. You loop over a set `iter`. So the loop will terminate after `card(iter)` iterations, no matter whether your termination criterion `abs(UB/LB) <= BdTol` is met.

I hope this helps!

Fred

Hi Martin, While there are ways to turn off domain checking (e.g. via $onUni ), this won't help here because the following domain violation would then also be accepted. foo[c] = 1; Since all subsets are based on the same superset, you could use the symbol's domain explicitly but then take only a sub...