## Can someone help me with GAMS Error 148 Topic is solved

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Bingo LI
User
Posts: 17
Joined: 2 years ago

### Can someone help me with GAMS Error 148

Hello all,
I have difficulties in solving my problem. Can someone help me with GAMS Error 148

Error Messages
148 Dimension different - The symbol is referenced with more/less
indices as declared
257 Solve statement not checked because of previous errors

Thank you,
Li
Attachments
Untitled_1.gms

Renger
Posts: 545
Joined: 3 years ago

### Re: Can someone help me with GAMS Error 148

Hi
You are trying to find the minimum of the variable ETA which is defined over the set i using an optimization approach.
In your case, you could just find the minimum of sum(t,p_pvf(i,t)*c_pv(i)):

Code: Select all

``````parameter
mymin
;

mymin = smin(i, sum(t,p_pvf(i,t)*c_pv(i)));
``````
In your formulation you have a i objective functions: you are trying to minimize each ETA instead of looking for the minimum of all ETA. Multi-
(take a look at https://en.wikipedia.org/wiki/Mathemati ... timization).
If you want to write an optimization problem, you have to write one objective function maximizing or minimizing one variable.
Cheers
Renger
____________________________________
Enjoy modeling even more: Read my blog on modeling at The lazy economist

Bingo LI
User
Posts: 17
Joined: 2 years ago

### Re: Can someone help me with GAMS Error 148

Hi Renger,
In my purpose, I exactly want to minimize each ETA (ETA(1), ETA(2), ETA(3)) because I want to utilize some distributed algorithm. And p_pvf(i,t) is a variable in my future formulation.
Could you give me some advice to write it under the rule "write one objective function maximizing or minimizing one variable"?
Thank you!
Li

Gideon Kruseman
User
Posts: 24
Joined: 2 years ago

### Re: Can someone help me with GAMS Error 148

Use the loop function.

Example in the attached file.

Gideon
Attachments
Untitled_2.gms
Gideon Kruseman
ex-ante and foresight lead @CIMMYT, big data focal point @CIMMYT, coordinator CoP socio-economic data @CGIAR_BigData

Bingo LI
User
Posts: 17
Joined: 2 years ago

### Re: Can someone help me with GAMS Error 148

It works
Thank you very much！！

Best,
Li