Search found 30 matches
- 1 year ago
- Forum: Syntax
- Topic: Help is needed with GDXXRW
- Replies: 1
- Views: 2247
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 ...
- 2 years ago
- Forum: Solvers
- Topic: Gap does not reduce beyond a certain percentage in a MIP
- Replies: 1
- Views: 3409
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...
- 2 years ago
- Forum: Syntax
- Topic: problem writing a subset from excel to gams
- Replies: 1
- Views: 3257
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 $gdxin Now I have another subset of x : y(x) How to import it from excel ? And how should I write it in excel? I tried it s...
- 2 years ago
- Forum: Tools
- Topic: NEOS option is not working
- Replies: 1
- Views: 3959
NEOS option is not working
I want to run my code from GAMS trial version to NEOS.
Earlier the option was available directly in GAMS Studio.
I uninstalled and installed GAMS. Now the option of NEOS is not available. The option is GREYED.
Can you please suggest, why is it so?
Earlier the option was available directly in GAMS Studio.
I uninstalled and installed GAMS. Now the option of NEOS is not available. The option is GREYED.
Can you please suggest, why is it so?
- 2 years ago
- Forum: Modeling
- Topic: Need help to formulate following conditionals in linear equations
- Replies: 4
- Views: 3532
Re: Need help to formulate following conditionals in linear equations
Thank you for your reply. Basically, I found the way , I should formulate the problem. However, modelling the problem in linear terms has become the problem for me. Please see this link : https://math.stackexchange.com/questions/4235264/help-required-to-formulate-a-linear-system-with-the-following-c...
- 2 years ago
- Forum: Modeling
- Topic: Need help to formulate following conditionals in linear equations
- Replies: 4
- Views: 3532
Re: Need help to formulate following conditionals in linear equations
Thank you for your reply. Can you please reply the name of the book. Thanks
- 2 years ago
- Forum: Modeling
- Topic: Need help to formulate following conditionals in linear equations
- Replies: 4
- Views: 3532
Need help to formulate following conditionals in linear equations
I want to formulate the set of linear equations for the following conditions: Q(i) = 0, if y(i) = 1 Q(i) = P(i), if sum(i,y(i)) = 0 Q(i) =P(i-r), if sum(i,y(i))$(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(...
- 2 years ago
- Forum: Modeling
- Topic: Problem related to formulating a MIP (MILP)
- Replies: 0
- Views: 3439
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...
- 2 years ago
- Forum: Modeling
- Topic: Help in writing linear equations based on conditionality in GAMS (9 variables)
- Replies: 6
- Views: 4310
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
Thanks
- 2 years ago
- Forum: Modeling
- Topic: Help in writing linear equations based on conditionality in GAMS (9 variables)
- Replies: 6
- Views: 4310
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