Search found 8 matches

by gnaeidj
1 month ago
Forum: Solvers
Topic: CPLEX time vs resUsd
Replies: 6
Views: 204

Re: CPLEX time vs resUsd

Hey Ghassem, to what value did you set the reslim? It seems that it was too low, your limit is 1000 and the resource usage is 1017. Can you post the last part of your code with the solver options? Mona Dear Mona yes, it was too low, so I set it to 5000. it took a long long time (almost 4 hours) and...
by gnaeidj
1 month ago
Forum: Solvers
Topic: CPLEX time vs resUsd
Replies: 6
Views: 204

Re: CPLEX time vs resUsd

The resUsd includes time to set up the model in Cplex and to report the solution to GAMS. For quadratic models it also included the time to extract the Q matrices from the non-linear instructions. Usually the time between resUsd and the time Cplex reports in the log is small and of not much practic...
by gnaeidj
2 months ago
Forum: Modeling
Topic: Modeling the absolute value
Replies: 21
Views: 1111

Re: Modeling the absolute value

Hi, the dollar command is used to manipulate the sets. For example, if the restrictions eq1, eq2, eq3 and eq4 does not apply to the last "t": eq1(n,m,t)$(ord(t) ne card(t)).. 1 - z(n,m,t) + z(n,m,t+1) + absvalue(n,m,t) =g= 1; eq2(n,m,t)$(ord(t) ne card(t)).. 1 - z(n,m,t) + 1-z(n,m,t+1) + 1-absvalue...
by gnaeidj
2 months ago
Forum: Modeling
Topic: Modeling the absolute value
Replies: 21
Views: 1111

Re: Modeling the absolute value

Just something I didn't catch
what did you mean by "$" command?
by gnaeidj
2 months ago
Forum: Modeling
Topic: Modeling the absolute value
Replies: 21
Views: 1111

Re: Modeling the absolute value

Thank you so much
by gnaeidj
2 months ago
Forum: Modeling
Topic: Modeling the absolute value
Replies: 21
Views: 1111

Re: Modeling the absolute value

Hi, Z is a binary variable and J is a scalar actually the Z variable represents a line status (being in circuit or out of it) and J represents the maximum number of lines which can get out of service I want to use the mentioned constraint to express the maximum number of switching in a system, but I...
by gnaeidj
2 months ago
Forum: Modeling
Topic: Modeling the absolute value
Replies: 21
Views: 1111

Re: Modeling the absolute value

Dear Friend I've Written a MIQCP code which has an absolute value in its constraints and I don't know how exactly I must write it so that the code works. here is the constraint: sum((n,m,t),abs(z(n,m,t) - z(n,m,t+1)) =l= 2*j the summation basically is based on t (time) and I want this absolute value...
by gnaeidj
7 months ago
Forum: Syntax
Topic: Error 143
Replies: 0
Views: 307

Error 143

Hi everyone I've got a problem while modeling my problem and I wanted you to help me, if you can so: My model contains a quadratic term in the objective function and this makes my Linear model non-linear. I tried to write the quadratic term separately as a condition and use its result as a first-ord...