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Nice analysis! I have a warning and a suggestion to make: The warning: Have in mind that in most cases CPLEX chooses to use its propietary and secret "dynamic search"... It is (AFAIK) "impossible" (unless you stop the solver at every iteration) to really know which nodes are bein...

I didn't understand well... but, I want that when x11 is equal to 1 (i1=math and k1=booklet1), z11 is equal to y11 or z12 is equal to y12 or z13 is equal to y13 or z14 is equal to y14. What about something like ? Uses an auxiliary variable w(i,k,o) z(i,o)-y(k,o) =l= ( 1- w(i,k,o) ) for all o z(i,o)-...

This is totally valid GAMS: Set G /'A','B','C'/ G1 /'A','B'/ G2 /'A','C'/; display G,G1,G2; G('A')=no; display G,G1,G2; The secret, as the original error message stated, is not to use G as the domain of G1/G2 and any other symbol. This is the positive side of not having domain definitions. The negat...

Hi all, I am facing a situation with model structure which I don't know what would be an elegant way to solve. In a prior version of a model I have a symbol which has dimension three: aSymbol(*,*,*) But now I want to use this symbol projected over a fourth set. aSymbol(aSet,*,*,*). This is of course...

You mean

https://www.gams.com/latest/docs/UG_Con ... Operations

?

Hi, checkout viewtopic.php?f=2&t=10058

Do you mean, Which of the elements of set time appear together with device B on a constraint or variable ?

Hi Yan: Check out this example, inspired with the help of the great Erwin at http://yetanothermathprogrammingconsultant.blogspot.it/2015/04/operating-on-empty-set.html $onempty set a /a1*a10/ set b(*) / /; variable x(a),dummy; equation r1,fobj; r1(a,b).. x(a)=e=1; fobj.. dummy=e=1; model c /all/; so...

Hi:

What do you want to accomplish ? Why not directly write the set IOZ to the file?

A parameter is intended to store a value mapped to each element of a set.

Good luck

Hi Lenilein, Is TC(i,j) a parameter (fixed in an instance of a solve) or a variable ? I get from your question that you intend to use it as a variable. Be aware that if it is a variable in your model, the smin() operator would require a DNLP solver ( http://old.gams.com/latest/docs/userguides/mccarl...