Search found 108 matches
- 6 years ago
- Forum: Syntax
- Topic: Getting error (rPower: FUNC DOMAIN: x**y, x < 0)
- Replies: 4
- Views: 5236
Re: Getting error (rPower: FUNC DOMAIN: x**y, x < 0)
First line of your linked support page: The power function power(x,y) is an integer power and thus the exponent y must be an integer. Looks to me like your exponent (0.3333) is not an integer.... This is the cause of your second error. The first error is caused by the "base" (x) not being ...
- 6 years ago
- Forum: Syntax
- Topic: local break-even point from mimized solutions
- Replies: 1
- Views: 2125
Re: local break-even point from mimized solutions
You will need to store the value of any variable that you want to know later between solves..
parameter teVal,zVal,finalVal;
SOLVE uc USING minlp MINIMIZING z;
zVal=z.l;
SOLVE uc USING minlp MINIMIZING te;
teVal=te.l;
finalVal=min(zVal,teVal);
parameter teVal,zVal,finalVal;
SOLVE uc USING minlp MINIMIZING z;
zVal=z.l;
SOLVE uc USING minlp MINIMIZING te;
teVal=te.l;
finalVal=min(zVal,teVal);
- 6 years ago
- Forum: Modeling
- Topic: About New Constraint
- Replies: 1
- Views: 2083
Re: About New Constraint
Hi Emine, perhaps you should keep this post in your original thread ? ( https://forum.gamsworld.org/viewtopic.php?f=9&t=10293 ). A general answer: If the problem is infeasible when you run it, you can generate a feasible solution by hand, fix the variables at this levels, and then find out which...
- 6 years ago
- Forum: Syntax
- Topic: If Statement - Uncontrolled Set entered as a costant
- Replies: 3
- Views: 3641
Re: If Statement - Uncontrolled Set entered as a costant
Hi, I understand that you want to fix the value of variable cg depending on the value of parameter pk. This code is one of the ways to accomplish this:
cg.fx(t)=47.898;
cg.fx(t)$(pk(t)=1)=36.367;
Best
Claudio
cg.fx(t)=47.898;
cg.fx(t)$(pk(t)=1)=36.367;
Best
Claudio
- 6 years ago
- Forum: Syntax
- Topic: Inverting sets
- Replies: 3
- Views: 3258
Re: Inverting sets
ehh... no ?
Is it exchanging the last and first element ? For example for n= 4
x(1,i+1) = x(4,i)
x(2,i+1) = x(2,i)
x(3,i+1) = x(3,i)
x(4,i+1) = x(1,i)
What do you mean by "inverted" ? Why is inverted(1)=3 and inverted(3)=1 ?n^-1 should mean, that it is the inverted value.
Is it exchanging the last and first element ? For example for n= 4
x(1,i+1) = x(4,i)
x(2,i+1) = x(2,i)
x(3,i+1) = x(3,i)
x(4,i+1) = x(1,i)
- 6 years ago
- Forum: Syntax
- Topic: Inverting sets
- Replies: 3
- Views: 3258
Re: Inverting sets
What does n^-1 means in this :
Are there always three members of n and the last and the first "exchange" each other sequentially ? ie:
x(1,1)=1
x(2,1)=2
x(3,1)=3
x(1,2)=3
x(2,2)=2
x(3,2)=1
x(1,3)=1
x(2,2)=2
x(3,3)=3
Are valid values ?
?x(n,i+1) = x(n^-1,i)
Are there always three members of n and the last and the first "exchange" each other sequentially ? ie:
x(1,1)=1
x(2,1)=2
x(3,1)=3
x(1,2)=3
x(2,2)=2
x(3,2)=1
x(1,3)=1
x(2,2)=2
x(3,3)=3
Are valid values ?
- 6 years ago
- Forum: Syntax
- Topic: Constraint involving cumulative sums
- Replies: 2
- Views: 2852
Re: Constraint involving cumulative sums
If I understand properly you may need another set:
alias(t,i);
y(i,j,k) =e= M - p(k) * ( sum(t$(ord(t)<ord(i)), y(t,j,k) ) - p(k) * ( sum(t$(ord(t)<ord(i)), y(j,t,k) )
Is this what you want ?
Best
Claudio
alias(t,i);
y(i,j,k) =e= M - p(k) * ( sum(t$(ord(t)<ord(i)), y(t,j,k) ) - p(k) * ( sum(t$(ord(t)<ord(i)), y(j,t,k) )
Is this what you want ?
Best
Claudio
- 6 years ago
- Forum: Modeling
- Topic: Connected Subgraph Generation
- Replies: 1
- Views: 2262
Re: Connected Subgraph Generation
This problem of course admits a MIP formulation, but you cannot easily (of the top of my head) limit it to generate only one subgraph per run. Of course this may not be a problem for you (since you are trying to enumerate them all). Something along the lines of... set node nodes; set edge(node,node)...
- 6 years ago
- Forum: Modeling
- Topic: hub network modelling
- Replies: 1
- Views: 2726
Re: hub network modelling
Fix the variables at the values of a solution that should be feasible and with a better value of the objective function, then try to run the problem.
The infeasible constraints are blocking this solution.
The infeasible constraints are blocking this solution.
- 6 years ago
- Forum: Syntax
- Topic: How to set upper value instead of level value
- Replies: 1
- Views: 2087
Re: How to set upper value instead of level value
do you mean
mindelay1(i,n,m) .. dee(i,n,m) - (v*y1(n,m)) =e= z(i,n) ;
?
Try to reformulate your question, at least for me its not understandable.
mindelay1(i,n,m) .. dee(i,n,m) - (v*y1(n,m)) =e= z(i,n) ;
?
Try to reformulate your question, at least for me its not understandable.