Hi,
I am experiencing a solver problem at the execution of GAMS file. I am trying to implement a two stage problem using stochastic programming similar to News Vendor Problem using emf (Extended Mathematical programming) solver. It comes up as
***status: Normal Completion
without any Erros but also having these two messages in .lst file
*** EMP syntax error: key expected: is neither a variable nor an equation: randvar (item 1 on line 2)
***
*** JAMS Pre processing failed
***
I have tried changing syntax but the issue remains and though its a Normal completion but it doesn't solve the uncertainity issue in the problem.
Can anyone please elaborate what could be the issue. I have attached my GAMS file.
•Capacity of 4th generator needs to be a decision variable.
•Capacity of 4th generator is stage1, as is the objective function.
•Cost of 5th generator (system buy price) is a random variable.
JAMS Pre Processing Failed - Solver Error
JAMS Pre Processing Failed - Solver Error
- Attachments
-
- gen4.gms
- (2.15 KiB) Downloaded 374 times
Re: JAMS Pre Processing Failed - Solver Error
Hi
I ran your model on my notebook (Gams 24.9.1 with CPLEX) and it runs fine. Here is the essential output:
What version of Gams and which solver are you using?
Cheers
Renger
I ran your model on my notebook (Gams 24.9.1 with CPLEX) and it runs fine. Here is the essential output:
Code: Select all
EXECUTION TIME = 0.172 SECONDS 4 MB 24.9.1 r63795 WEX-WEI
GAMS 24.9.1 r63795 Released Aug 30, 2017 WEX-WEI x86 64bit/MS Windows 07/14/18 16:37:20 Page 5
G e n e r a l A l g e b r a i c M o d e l i n g S y s t e m
Solution Report SOLVE gen4 Using EMP From line 64
S O L V E S U M M A R Y
MODEL gen4 OBJECTIVE obj
TYPE EMP DIRECTION MINIMIZE
SOLVER JAMS FROM LINE 64
**** SOLVER STATUS 1 Normal Completion
**** MODEL STATUS 1 Optimal
**** OBJECTIVE VALUE 9919800000.0000
RESOURCE USAGE, LIMIT 0.079 1000.000
ITERATION COUNT, LIMIT 0 2000000000
EVALUATION ERRORS 0 0
JAMS 1.0 24.9.1 r63795 Released Aug 30, 2017 WEI x86 64bit/MS Windows
JAMS - Solver for Extended Mathematical Programs (EMP)
------------------------------------------------------
*** Problems reading JAMS info file: c:\Users\renge\Downloads\225a\empinfo.dat
---
--- No reformulations requested
--- Generating unchanged scalar model
---
--- The model c:\Users\renge\Downloads\225a\emp.dat will be solved by GAMS
---
--- Returning from GAMS step
IBM ILOG CPLEX 24.9.1 r63795 Released Aug 30, 2017 WEI x86 64bit/MS Windows
Cplex 12.7.1.0
Space for names approximately 0.00 Mb
Use option 'names no' to turn use of names off
LP status(1): optimal
Cplex Time: 0.02sec (det. 0.01 ticks)
Optimal solution found.
Objective : 9919800000.000000
---
--- Equations skipped = 0 Equations added = 0
--- Variables skipped = 0 Variables added = 0
---
Cheers
Renger
____________________________________
Enjoy modeling even more: Read my blog on modeling at The lazy economist
Enjoy modeling even more: Read my blog on modeling at The lazy economist
Re: JAMS Pre Processing Failed - Solver Error
Hi Renger,
Thanks for your reply. I am using;
GAMSIDE build 63619 / 63795
GAMS Release 24.9.1 r63795 WEX-WEI x86 64bit/MS Windows
Release Date Released Aug 30, 2017
License Date Aug 30, 2017
Yes, it gives me a deterministic model with emp as I have put the 2nd stage in comments in .gms file; If you remove the following asterisks in the main file and try to solve it with 2 stage stochastic programming, it gives an error and I am unable to sort it out.
*file emp / '%emp.info%' /; put emp '* problem %gams.i%'/;
*$onput
*randvar c5 discrete 0.7 60
* 0.2 50
* 0.1 40
*stage 2 g1_ut g2_ut g3_ut g5_ut c5
*stage 2 demand_satisfaction gen1_utilisation gen2_utilisation gen3_utilisation gen4_utilisation gen5_utilisation
*$offput
*putclose emp;
Thanks
Thanks for your reply. I am using;
GAMSIDE build 63619 / 63795
GAMS Release 24.9.1 r63795 WEX-WEI x86 64bit/MS Windows
Release Date Released Aug 30, 2017
License Date Aug 30, 2017
Yes, it gives me a deterministic model with emp as I have put the 2nd stage in comments in .gms file; If you remove the following asterisks in the main file and try to solve it with 2 stage stochastic programming, it gives an error and I am unable to sort it out.
*file emp / '%emp.info%' /; put emp '* problem %gams.i%'/;
*$onput
*randvar c5 discrete 0.7 60
* 0.2 50
* 0.1 40
*stage 2 g1_ut g2_ut g3_ut g5_ut c5
*stage 2 demand_satisfaction gen1_utilisation gen2_utilisation gen3_utilisation gen4_utilisation gen5_utilisation
*$offput
*putclose emp;
Thanks