[SCIP] Coding in ZIMPL regarding

[Ambros Gleixner]

Dear Shahul,

You need to use the "if then" and the "and" keywords.  This is explained 
in an example on page 16 and 17 of the Zimpl manual

http://zimpl.zib.de/download/zimpl.pdf


Best,
Ambros


> Von: Shahul Hameed K K [mailto:Shahul.Hameed at ibsplc.com]
> Gesendet: Donnerstag, 19. Januar 2017 06:49
> An: kasse at zib.de
> Betreff: Coding in ZIMPL regarding
>
>
>
> Dear sir,
>
>
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> I am Shahul Hameed K K, from India. I am a  post graduate in operations research.  I need to code an LP problem in LPSolve IDE using ZIMPL. But unfortunately I am not getting the required assistance from anywhere including the group.
>
>
>
> I have thoroughly gone through the ZIMPL manual. I need assistance basically in writing the constraints. I started modelling in ZIMPL which is not complete , I am trying to assign trips on aircrafts;
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> set TRIPS:= {read "trip.txt" as "<1n>"};
>
> set AIRCRAFTS:={read "tail.txt" as "<1n>"};
>
> set TA:=  TRIPS * AIRCRAFTS;
>
>
>
> param arrTime[TRIPS]:= read "arrTime.txt" as "<1n> 2n";
>
> param depTime[TRIPS]:= read "depTime.txt" as "<1n> 2n";
>
> param cost[TA]:= read "cost.txt" as "<1n,2n> 3n";
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>
> var x[TA] binary;
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> minimize totalcost: sum <t,a> in TA: cost[t,a] * x[t,a];
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> subto constraint1:
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> forall<t> in TRIPS do
>
> sum<a> in AIRCRAFTS: x[t,a] ==1;
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> now I need to write another constraint,
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> forall(a in aircrafts, t in trips) sum( k in trips such that arrTime[k] > depTime[t] and deptime[k] < arrTime[t]) x[k,a] = (1 – x[t,a])*10;
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> How to write this? Could you please help me ? I am urgently in need of this. I actually started doing in CPLEX but I need to do it in open solver now?
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> Looking forward to your response and thank you in advance.
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> Regards,
>
> Shahul


-- 
Ambros Gleixner, Zuse Institute Berlin, http://www.zib.de/gleixner