Search found 30 matches

by parag_patil
1 year ago
Forum: Syntax
Topic: Help is needed with GDXXRW
Replies: 1
Views: 2180

Help is needed with GDXXRW

Hello, I have multiple parameters to be imported from excel sheet. Currently, I am using multiple $call gdxxrw as follows: $call GDXXRW o=scold.gdx i=input_data.xlsx trace=3 set=scold rng= set_vert_streams!g2 rdim=1 $call GDXXRW o=shot.gdx i=input_data.xlsx trace=3 set=shot rng= set_vert_streams!h2 ...
by parag_patil
2 years ago
Forum: Solvers
Topic: Gap does not reduce beyond a certain percentage in a MIP
Replies: 1
Views: 2706

Gap does not reduce beyond a certain percentage in a MIP

Dear all, I am solving an MIP problem. It is considerably large. While the gap reduces initially, (from 375 to 14 %). Beyond this, it does not move forward. Can you please let me know, what can I do? I have already tried many cplex parameters. But are not fruitful. log_file_reference.txt Solver is C...
by parag_patil
2 years ago
Forum: Syntax
Topic: problem writing a subset from excel to gams
Replies: 1
Views: 2607

problem writing a subset from excel to gams

I have a set : x containing x1,x2. I take it from an excel sheet using following code: $call GDXXRW o=x.gdx i=x_data.xlsx trace=3 set=x rng=x_set!a1 rdim=1 $GDXIN x.gdx $LOAD x $gdxin Now I have another subset of x : y(x) How to import it from excel ? And how should I write it in excel? I tried it s...
by parag_patil
2 years ago
Forum: Tools
Topic: NEOS option is not working
Replies: 1
Views: 3260

NEOS option is not working

I want to run my code from GAMS trial version to NEOS.
Earlier the option was available directly in GAMS Studio.
I uninstalled and installed GAMS. Now the option of NEOS is not available. The option is GREYED.

Can you please suggest, why is it so?
by parag_patil
2 years ago
Forum: Modeling
Topic: Need help to formulate following conditionals in linear equations
Replies: 4
Views: 3375

Re: Need help to formulate following conditionals in linear equations

Thank you for your reply. Basically, I found the way , I should formulate the problem. However, modelling the problem in linear terms has become the problem for me. Please see this link : https://math.stackexchange.com/questions/4235264/help-required-to-formulate-a-linear-system-with-the-following-c...
by parag_patil
2 years ago
Forum: Modeling
Topic: Need help to formulate following conditionals in linear equations
Replies: 4
Views: 3375

Re: Need help to formulate following conditionals in linear equations

Thank you for your reply. Can you please reply the name of the book. Thanks
by parag_patil
2 years ago
Forum: Modeling
Topic: Need help to formulate following conditionals in linear equations
Replies: 4
Views: 3375

Need help to formulate following conditionals in linear equations

I want to formulate the set of linear equations for the following conditions: Q(i) = 0, if y(i) = 1 Q(i) = P(i), if sum(i,y(i)) = 0 Q(i) =P(i-r), if sum(i,y(i))$(ord(i)<r) and y(i)$(ord(i)=r)=1 and y(i) =0 Here set i,r; alias(i,r); Parameter P(i) "arbitrary vector of length i"; Variable Q(...
by parag_patil
2 years ago
Forum: Modeling
Topic: Problem related to formulating a MIP (MILP)
Replies: 0
Views: 2801

Problem related to formulating a MIP (MILP)

I want the following help in linear fashion: I have a vector (parameter) : Z = [1 2 3 4 5 ............n]. I have binary variables with length of Z : y(1),y(2).....y(n) A new vector, 'Z_new' is needed as follows: such that, if y(i) is 1, then the ith element in Z_new should be zero. For example, if y...
by parag_patil
2 years ago
Forum: Modeling
Topic: Help in writing linear equations based on conditionality in GAMS (9 variables)
Replies: 6
Views: 4209

Re: Help in writing linear equations based on conditionality in GAMS (9 variables)

Hi, still I did not understand. If it is possible, can you write the correct answer please? I'm trying it since few days. I'm not able to get it done.

Thanks
by parag_patil
2 years ago
Forum: Modeling
Topic: Help in writing linear equations based on conditionality in GAMS (9 variables)
Replies: 6
Views: 4209

Re: Help in writing linear equations based on conditionality in GAMS (9 variables)

I appreciate your help ( suggesting big M method), but it is giving wrong answer, when applied to 2 binary variable problem