Search found 340 matches

by bussieck
2 months ago
Forum: Modeling
Topic: Problem is unbounded
Replies: 3
Views: 116

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
2 months ago
Forum: Modeling
Topic: Problem is unbounded
Replies: 3
Views: 116

Re: Problem is unbounded

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

-Michael
by bussieck
2 months ago
Forum: Solvers
Topic: solution for GAMS code
Replies: 4
Views: 205

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
2 months ago
Forum: Announcements
Topic: Job opportunity in the European Commission in Seville (Spain)
Replies: 1
Views: 375

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
2 months ago
Forum: Modeling
Topic: Division by zero
Replies: 9
Views: 307

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
2 months ago
Forum: Modeling
Topic: Double Exponent in Objective Function
Replies: 5
Views: 207

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...
by bussieck
2 months ago
Forum: Modeling
Topic: Division by zero
Replies: 9
Views: 307

Re: Division by zero

I guess something goes wrong when you read data from Excel. As Auke says, gdxxrw seems not successful reading the spreadsheet. EMMA.gms ignores good practice when calling an external program: Make sure the return code is good. $IFTHEN %LOADDATA% == '1' $CALL GDXXRW.exe input\data_ts.xlsx @data_ts.tx...
by bussieck
2 months ago
Forum: Modeling
Topic: Division by zero
Replies: 9
Views: 307

Re: Division by zero

Instead of pictures please attach the text files. In any case, the line number mentioned in the execution error refers to the line number in the echo print of the input file (see https://www.gams.com/latest/docs/UG_GAMSOutput.html#UG_GAMSOutput_EchoPrintOfTheInputFile). The echo print might be suppr...
by bussieck
2 months ago
Forum: Syntax
Topic: Help with gams, gdx and xlsx
Replies: 6
Views: 267

Re: Help with gams, gdx and xlsx

I have no problems whatsoever reading the data with gdxxrw with the following code: $onecho > gdxxrw.in i=Tablas_Alturas.xlsx o=data.gdx par=DH1 rng=H1(K0,J01)!A1:B7 par=DH2 rng=H2(K0,J02)!A1:AB7 par=DH3 rng=H3(K0,ND01)!A1:I8 $offecho $call gdxxrw @gdxxrw.in $if errorlevel 1 $abort "problems with gd...
by bussieck
2 months ago
Forum: Solvers
Topic: the solver found integer solution
Replies: 11
Views: 494

Re: the solver found integer solution

MIP is a hard problem type and even small models might not solve even with years of computing time. Perhaps there are better model formulations of your problem (hard to suggest anything without your code). The reason for the 4/14 return code might be some other limit (e.g. memory) kicking in. The 14...