Search found 30 matches

by Luqman Hakeem
3 years ago
Forum: Syntax
Topic: Fixing binary variable
Replies: 8
Views: 18895

Re: Fixing binary variable

I need a bit more favor from you. My scenario is now changed a little bit.
Since retrofitting cost cash flow occurs only once. It means I want n(i,j,t) to be equal to 1 only once and the time when for any power plant 'i', V(i,j,t) becomes 1 for the first time.
by Luqman Hakeem
3 years ago
Forum: Syntax
Topic: Fixing binary variable
Replies: 8
Views: 18895

Re: Fixing binary variable

Thank you so much. Now it is working perfectly fine.
by Luqman Hakeem
3 years ago
Forum: Syntax
Topic: Changing Index of Variables
Replies: 4
Views: 8534

Re: Changing Index of Variables

Sorry to interept you again.

Big M formulation did not worked. Files are attached.
LGDPFSwlosses4.gms
(53.07 KiB) Downloaded 250 times
input26.xlsx
(2.96 MiB) Downloaded 249 times
by Luqman Hakeem
3 years ago
Forum: Syntax
Topic: Fixing binary variable
Replies: 8
Views: 18895

Re: Fixing binary variable

Thanks for your time.

Sorry to bother you but it is not working.
by Luqman Hakeem
3 years ago
Forum: Syntax
Topic: Changing Index of Variables
Replies: 4
Views: 8534

Re: Changing Index of Variables

Thanks! Actually when fuel switching is done from coal to natural gas (NG) then all the parameters for a certain power plant should be changed. For example fuel cost should be changed from coal to NG. I tried it as: FC(i,'Oil',t)$(hOil(i,tc)=1) = FC(i,'NG',t); VC(i,'Oil',t)$(hOil(i,tc)=1) = VC(i,'NG...
by Luqman Hakeem
3 years ago
Forum: Syntax
Topic: Fixing binary variable
Replies: 8
Views: 18895

Re: Fixing binary variable

Hi! Thanks for your kind suggestion. Actually, n(i,j,t) binary varibale is associated with retrofitting cost. Once retrofitting is done, it will remain over there for the rest of the time (for which i want to fix n(i,j,t)). Whereas, V(i,j,t) is binary variable for operation. If plant is operational ...
by Luqman Hakeem
3 years ago
Forum: Syntax
Topic: Changing Index of Variables
Replies: 4
Views: 8534

Changing Index of Variables

Hi! I am currently working on the modelling of fuel switching in GAMS. In fuel switching, fuel of certain power plant is changed from more carbon intensive fuel (e.g. coal) to less carbon intensive fuel (e.g. natural gas). Binary variable is attached with fuel switching in order to check its feasibi...
by Luqman Hakeem
3 years ago
Forum: Syntax
Topic: Fixing binary variable
Replies: 8
Views: 18895

Fixing binary variable

Hi! I am currently working on a model that is quite lengthy. But in simple words, i want to fix a binary variable (nijt) as soon as other binary varibale (Vijt) becomes one. I tried to implement it as if(sum((i,j), V.L(i,j,t) =1), n.fx(i,j,t)$(n.L(i,j,t) = 1) = 1; ); But it didn't worked. Can anybod...
by Luqman Hakeem
3 years ago
Forum: Syntax
Topic: If Condition Over Binary Variables
Replies: 1
Views: 3824

If Condition Over Binary Variables

Hello everybody,
Hope everyone is fine.
I am currently facing a problem regarding 'if' condition over binary variables. I applied $ condition but it resulted in error.
Mathematically,
" if sum((p,q), Z(p,q,t) <126)
then sum(a, n(a,t)) = 0 "
Thanks in advance.
by Luqman Hakeem
3 years ago
Forum: Syntax
Topic: Loop for objective function
Replies: 34
Views: 313495

Re: Loop for objective function

Hi I think you could do without t in H(i,t). Then, if in year x, H(i) becomes 1, you fix it to that level and it will stay like this in all t afterwards. if(h(i) = 1; h.FX(i) = 1;); Cheers Renger Hi Renger, Your idea is good as always. But it is showing following errors. input2.xlsx 141 Symbol decl...