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Re: [Bug-glpk] expression following = has invalid type
From: |
Andrew Makhorin |
Subject: |
Re: [Bug-glpk] expression following = has invalid type |
Date: |
Sun, 11 Jun 2017 09:22:51 +0300 |
On Sun, 2017-06-11 at 04:41 +0200, Ahmed Shahein wrote:
> Dear Madam/Sir,
>
>
> I have tried to compile the attached AMPL model using the GLPK solver
> however, it gave me the following error message:
>
>
> GLPSOL: GLPK LP/MIP Solver, v4.55
> Parameter(s) specified in the command line:
> --model fir.mod
> Reading model section from fir.mod...
> fir.mod:20: expression following = has invalid type
> Context: 0 ] + sum { k in 1 .. n - 1 } 2 * r [ k ] * cos ( k * o ) ;
> MathProg model processing error
>
>
>
>
>
> When I posted the code at the AMPL forum I received a reply that they
> managed to compile the code using another solver.
>
>
> The AMPL fourms link is:
> https://groups.google.com/forum/#!topic/ampl/1HpbT3Rfi1U
>
>
> Is this a bug, or a limited feature?
The latter. Not all AMPL features are implemented in GNU MathProg.
> Do you have any suggestion(s) to overcome this issue?
You may replace the statement
var R {o in OMEGA} = r[0] + sum{k in 1..n-1} 2*r[k]*cos(k*o);
which is incorrect in MathProg, with the following ones:
var R {o in OMEGA};
s.t. foo{o in OMEGA}: R[o] = r[0] + sum{k in 1..n-1} 2*r[k]*cos(k*o);
>
>
> Thanks in advance.
>
>
> Regards.
>
>
> Ahmed.
>
>
> --
> Ahmed Shahein
>
> HW Design Engineer
>
- Re: [Bug-glpk] expression following = has invalid type,
Andrew Makhorin <=