Search found 10 matches

by ikeato
5 years ago
Forum: Syntax
Topic: Scheduling using precedence
Replies: 0
Views: 3220

Scheduling using precedence

Hi, I am currently working on a scheduling problem which involves adding a precedence constraint to the model. sets i 'number of blocks' /1,2,36,1851,1885,3,37,1852,1886/ mcs 'number of mutually exclusive sets' /1*7/ mc(mcs,i)'specification of mutually exclusive projects' /1.(2,3,36), 2.(1,36), 3.(1...
by ikeato
5 years ago
Forum: Syntax
Topic: Data Exchange (Excel) to GAMS
Replies: 3
Views: 4866

Re: Data Exchange (Excel) to GAMS

Hi Renger,

I have been able to sort it out.

It's because I was calling the set from excel into GAMS using "dset" instead of "set".

It worked when I changed it.

Regards,
Isaac
by ikeato
5 years ago
Forum: Syntax
Topic: Data Exchange (Excel) to GAMS
Replies: 3
Views: 4866

Re: Data Exchange (Excel) to GAMS

Hi Renger,

Thanks for the assistance.

Please I tried it but it gives an error that the dimension of a domain should be 1 for mc.


I have attached the excel and GAMS for your review.


Regards,

Isaac
by ikeato
5 years ago
Forum: Syntax
Topic: Data Exchange (Excel) to GAMS
Replies: 3
Views: 4866

Data Exchange (Excel) to GAMS

Hi, I have been working with GAMS (newbie) and having an issue with dealing with a lot of data which is more than the number required in excel (.xlsx), thus my data is more than 1million. Please what is the best way to overcome this problem? Secondly I have to import Set mc (shown below) data from E...
by ikeato
5 years ago
Forum: Syntax
Topic: Precedence constraint
Replies: 4
Views: 3417

Re: Precedence constraint

Hi Renger,

Thanks for the effort.

Please how do you write a normal gams equation to show that 1 should come before 2 then 3 then 4 in a given set j, whereby 1 with a quantity has to be filled up before 2 then 3 and 4?

Regards,
Ike.
by ikeato
5 years ago
Forum: Syntax
Topic: Precedence constraint
Replies: 4
Views: 3417

Re: Precedence constraint

Hi Renger,

Please find attached model.

Thanks,
Ike
by ikeato
5 years ago
Forum: Syntax
Topic: Precedence constraint
Replies: 4
Views: 3417

Precedence constraint

Hi, Please find below the gams equation with comments. I have run the gams model but the phase precedence constraint is not working. For example phase 1 has to filled up before phase 2 and so on. Equation: LowPreceCons1(t).. sum(jp3,Ym(jp3,t)) - sum(jp3,Qpm(jp3)*W(jp3+1,t))=G=0; "this is the eq...
by ikeato
6 years ago
Forum: Syntax
Topic: Repititive equations over time
Replies: 0
Views: 2059

Repititive equations over time

Hi, Am writing a code where I have to cater for when time is 1 and the next equation is supposed to be when t is 1 plus t =2, and it follows where when the next equation is when t=1 plus when t=2 plus when t=3. Below is the equation: set t periods /1*3/ Prece6cons1(t).. SW*sum((b,i,j,Fpr),deff(b,t,i...
by ikeato
6 years ago
Forum: Syntax
Topic: Errors 654, 409, 148,125
Replies: 2
Views: 3070

Re: Errors 654, 409, 148,125

Thanks for the insight.
Am sorted.
by ikeato
6 years ago
Forum: Syntax
Topic: Errors 654, 409, 148,125
Replies: 2
Views: 3070

Errors 654, 409, 148,125

Hi, Working a some codes and I keep getting these errors 654, 409,148,125 on these equations: objectivefunction.. z =e= (sum(i,j), Ah * LD(i,j) * x(i,j)+ Bh * DL(j,i)* y(j,i)); cograde(i).. gl =l= (sum(i,j), g(i) * P * x(i,j))/(sum(i,j) ,P * x(i,j))=l= gu; This is my full codes: Sets i loading index...