Search found 344 matches

by bussieck
4 months ago
Forum: Syntax
Topic: Euclidean metric
Replies: 1
Views: 123

Re: Euclidean metric

You need to describe your problem better before you can get help here. Read the guidelines of the forum.

-Michael
by bussieck
4 months ago
Forum: Modeling
Topic: Modeling the absolute value
Replies: 23
Views: 6713

Re: Modeling the absolute value

Look at GAMS Model Library model absmip (https://www.gams.com/latest/gamslib_ml/ ... bsmip.html) This shows how to linearly (with discrete variables) model abs, min, max, and sign.

-Michael
by bussieck
4 months ago
Forum: Modeling
Topic: Double Exponent in Objective Function
Replies: 5
Views: 286

Re: Double Exponent in Objective Function

That's a totally different question. If you turn a linear coefficient into a non-linear one this can have all sorts of effects depending on the model, e.g. this want allow the variable to becomes negative. So without specifics it's hard to say what is going on. Why don't you be precise and tell us h...
by bussieck
4 months ago
Forum: Solvers
Topic: solution for GAMS code
Replies: 4
Views: 282

Re: solution for GAMS code

You better know the semantic of your variables and how to produce a solution that makes sense to the user question. Not sure how I can help. Try to be more specific in your question.

-Michael
by bussieck
4 months ago
Forum: Modeling
Topic: Problem is unbounded
Replies: 3
Views: 171

Re: Problem is unbounded

When I run this it solves to optimality: S O L V E S U M M A R Y MODEL Refinery OBJECTIVE totalprofit TYPE LP DIRECTION MAXIMIZE SOLVER MINOS FROM LINE 121 **** SOLVER STATUS 1 Normal Completion **** MODEL STATUS 1 Optimal **** OBJECTIVE VALUE 255000000.0000 RESOURCE USAGE, LIMIT 0.015 1000.000 ITER...
by bussieck
4 months ago
Forum: Modeling
Topic: Problem is unbounded
Replies: 3
Views: 171

Re: Problem is unbounded

It's hard to run this without the data. You might want to attach data_input.xlsx.

-Michael
by bussieck
4 months ago
Forum: Solvers
Topic: solution for GAMS code
Replies: 4
Views: 282

Re: solution for GAMS code

The model is small enough for the demo system. Check the listing (lst) file to look at the solution.

-Michael
by bussieck
4 months ago
Forum: Announcements
Topic: Job opportunity in the European Commission in Seville (Spain)
Replies: 1
Views: 786

Job opportunity in the European Commission in Seville (Spain)

The Unit "Economics of Agriculture" located in Seville (Spain) is part of the European Commission's Joint Research Centre. It has a job opportunity for an Economic Researcher with the following profile: Economic Modeller - National analysis of African countries with CGE Call ref. 2019-SVQ-D4-FGIV-01...
by bussieck
4 months ago
Forum: Modeling
Topic: Division by zero
Replies: 9
Views: 415

Re: Division by zero

Leo, the additions I made were not there to make a difference for the data issues. They were there to catch ($abort) if the gdxxrw misbehaves (reports an error) which is does not the case. It just reads zero for your parameter. We would need to see the Excel file to see why this is. I don't think th...
by bussieck
4 months ago
Forum: Modeling
Topic: Double Exponent in Objective Function
Replies: 5
Views: 286

Re: Double Exponent in Objective Function

Test and Test2 are not equal: set t /1*5/; parameter CEMUTOTPER(t); CEMUTOTPER(t) = 5; parameter Test; parameter Test2; Test = (power((sum(t, CEMUTOTPER(t))),2))**0.5; Test2 = sum(t, CEMUTOTPER(t)) scalar diff; diff = test-test2; display Test, Test2, diff; ---- 75 PARAMETER Test = 25.000 PARAMETER T...