[Top][All Lists]

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
## Re: [Help-glpk] A MathProg question

**From**: |
glpk xypron |

**Subject**: |
Re: [Help-glpk] A MathProg question |

**Date**: |
Tue, 13 Nov 2012 15:31:01 +0100 |

Hello Reg,
sum{i in I} w[i]
is a linear function of w[i].
max{i in I} w[i]
is not a linear function of w[i].
GLPK can only solve linear problems.
You can still solve your problem as follows:
var w{i in I};
var obj;
minimize err: obj;
s.t. c{i in I} obj >= w[i];
Best regards
Xypron
-------- Original-Nachricht --------
>* Datum: Tue, 13 Nov 2012 05:54:03 -0800 (PST)*
>* Betreff: [Help-glpk] A MathProg question*
>* *
>* *
>* Why is:*
>* *
>* minimize err : sum{i in I} w[i];*
>* *
>* acceptable, but:*
>* *
>* minimize err : max{i in I} w[i];*
>* *
>* is not?*
>* *
>* I can get the desired result by following example cf12b.mod, but I'm*
>* puzzled why glpsol 4.47 emits an error. From reading the manual, I'd expect*
>* that any of the iterated operators would be linguistically interchangeable w/*
>* sum.*
>* *
>* Thanks,*
>* Reg*
>* *
>* *
>* _______________________________________________*
>* Help-glpk mailing list*
>* address@hidden*
>* https://lists.gnu.org/mailman/listinfo/help-glpk*