Search found 87 matches

by Fred
1 day ago
Forum: Syntax
Topic: PROBLEM WITH FONT
Replies: 2
Views: 26

Re: PROBLEM WITH FONT

Hi, I guess you try to use Studio in combination with the Mojave dark mode. That doesn't work right now, see the 26 release notes:
https://www.gams.com/latest/docs/RN_26. ... 610_STUDIO

Hope this helps,
Fred
by Fred
3 days ago
Forum: Modeling
Topic: Speed up model generation time when using loop
Replies: 3
Views: 41

Re: Speed up model generation time when using loop

Hi Feifan, The GAMS OO API class GAMSModelInstance provides access to a model instance that can be modified and resolved without regenerating the model over and over. (see e.g. the transport 7 example from the Python API Tutorial: https://www.gams.com/latest/docs/API_PY_TUTORIAL.html#PY_CREATE_MODEL...
by Fred
3 days ago
Forum: Syntax
Topic: Manipulatiing parameters - Assignment problem due to different dimension
Replies: 2
Views: 49

Re: Manipulatiing parameters - Assignment problem due to different dimension

Hi, If I understand you correctly, you somehow need to compare the set elements of set w 'windspeed'; to the parameter values of Parameter speed(i,j,k) 'Speed'; In your approach you basically try to replace set w with parameter speed(i,j,k) which - as you already noticed - does not work that way. Ho...
by Fred
3 days ago
Forum: Modeling
Topic: Speed up model generation time when using loop
Replies: 3
Views: 41

Re: Speed up model generation time when using loop

Hi, if the model rim is always the same and you know all the parameters in advance (i.e. sceanrio 2 dose not depend on the solution of scenario 1 etc), GUSS might be what you are looking for: https://www.gams.com/latest/docs/S_GUSS.html If you are willing to share your model (and data) to allow othe...
by Fred
1 week ago
Forum: Modeling
Topic: GAMS/CPLEX return infeasibility while DICOPT give a solution
Replies: 3
Views: 55

Re: GAMS/CPLEX return infeasibility while DICOPT give a solution

Hi, What version did you use? With the latest GAMS 26.1.0/CPLEXD, Cplex solves the problem even if I remove all variable fixes. --- Job Untitled_42.gms Start 03/13/19 07:04:46 26.1.0 rf2b37b9 WEX-WEI x86 64bit/MS Windows GAMS 26.1.0 Copyright (C) 1987-2019 GAMS Development. All rights reserved [...]...
by Fred
1 month ago
Forum: Modeling
Topic: Aggregate Planning... would appreciate any help... thanks
Replies: 1
Views: 206

Re: Aggregate Planning... would appreciate any help... thanks

Hi, Can you explain why exactly you think that the number of spent hours Ru(t) of the workers is not reflected fully in the solution ? And can you also explain what is meant by [...] it doesn't look like it calculated all the (i) Looking at the solution listing I see man hours of regular labor in ev...
by Fred
1 month ago
Forum: Syntax
Topic: Results in the right order/position of the week
Replies: 4
Views: 190

Re: Results in the right order/position of the week

Hi, If I understand you correctly, you basically want to map 7 daily solutions of hours 1...24 to the hours of week 1...168 day1 1...24 --> 1..24 day2 1...24 --> 25..48 ... day7 1...24 --> 145..168 The following should do he trick: set d days /d1*d7/; loop(d, * some solve statements that gives you X...
by Fred
1 month ago
Forum: Syntax
Topic: Results in the right order/position of the week
Replies: 4
Views: 190

Re: Results in the right order/position of the week

Hi, The "Uncontrolled set" refers to t2 which you are using on the right hand side of the assignment without controlling it. You could either replace the ord() stuff by just using t2 on the left hand side as well Xpar(i,t2) = X.l(i,t2); or you might want to declare variable X over super set t1 and t...
by Fred
1 month ago
Forum: Syntax
Topic: Incremental summing in equation
Replies: 2
Views: 85

Re: Incremental summing in equation

Hi, The following should do the trick: set i /i1*i5 /; alias (i,ii); variable x(i); equation y(i); y(i).. sum(ii$(ord(ii)<=ord(i)),x(ii)) =l= 15; [...] The following links to the documentation explain the alias and ord operator: https://www.gams.com/latest/docs/UG_SetDefinition.html#UG_SetDefinition...
by Fred
2 months ago
Forum: Syntax
Topic: CHOOSING A SPECIFIC OPTIMAL SOLUTION FROM A PARETO FRONT GENERATED IN GAMS
Replies: 2
Views: 185

Re: CHOOSING A SPECIFIC OPTIMAL SOLUTION FROM A PARETO FRONT GENERATED IN GAMS

Hi, You could store the values of x1 and x2 in a parameter, similar to how it is done for the objective values in the example, e.g. loop(counter, E = (ranges('OF2max') - ranges('OF2min'))*(ord(counter) - 1)/(card(counter) - 1) + ranges('OF2min'); of2.lo = E; solve pareto1 using nlp maximizing of1; r...