Re: [Help-glpk] forall constraint in MathProg

[Xypron]

Hello Noli,

could you provide the condition you want to formulate in mathematical
notation?

"forall" is used for logical expression. Did you mean "sum"?
Instead of "p in 1..PERIOD" you may want to write "p in {1..PERIOD}".
If p is a number {pp in p} does not make sense.

Please, save the gmpl text below as test.mod, and run command.
glpsol -m test.mod --check --wlp test.lp

Check if test.lp contains the constraints you meant to write.

Best regards

Xypron

# file test.lp
param nperiod := 3;
param nnature := 20;
param nstand := 20;
set PERIOD := {1..nperiod};
set NATURE := {1..nnature};
set STAND := {1..nperiod};
param standarea {STAND} := 5 + 5 * Uniform01();
var forest{STAND, PERIOD};
var nh{NATURE, PERIOD};
s.t. habitat{p in PERIOD, n in NATURE, s in STAND} :
  sum{pp in PERIOD:pp <= p} forest[s, pp] + nh[n, p] = standarea[s];
end;


On 05.11.2012 19:29, Noli Sicad wrote:
> Hi,
>
> I am trying to translate this set of LINDO constraint (below) into
> MathProg. But I don't have any success.
>
> ######
>
> 37) S1P1 + N1P1 = 12.3
> 38) S1P1 + S1P2 + N1P2 = 12.3
> 39) S1P1 + S1P2 + S1P3 + N1P3 = 12.3
>
> 40) S2P1 + N2P1 = 35.6
> 41) S2P1 + S2P2 + N2P2 = 35.6
> 42) S2P1 + S2P2 + S2P3 + N2P3 = 34.6
>
> 43) S3P1 + N3P1 = 34.6
> 44) S3P1 + S3P2 + N3P2 = 34.6
> 45) S3P1 + S3P2 + S3P3 + N3P3 = 34.6
>
> .
> .
> .
>
> 94) S20P1 + N20P1 = 46.0
> 95) S20P1 + S20P2 + N20P2 = 46.0
> 96) S20P1 + S20P2 + S20P3 + N20P3 = 46.0
>
> ###########
>
> I tried to implement like this:
>
> subject to Habitat_Constraint{ p in 1..PERIOD, n in 1..NATURE, s in STAND}:
>    forall {pp in p} Forest[s,pp] + NH[n,p] = StandArea[s];
>
> However, I got this error below.
>
> #######
> Running tool: GLPK/MathProg
>
> GLPSOL: GLPK LP/MIP Solver, v4.47
> Parameter(s) specified in the command line:
>  --math Model_I_1_original_5-evenflow_even-acres_OF_alter3.mod
> Reading model section from
> Model_I_1_original_5-evenflow_even-acres_OF_alter3.mod...
> Model_I_1_original_5-evenflow_even-acres_OF_alter3.mod:77: domain
> expression has invalid type
> Context: ...ERIOD , n in 1 .. NATURE , s in STAND } : forall { pp in p }
> MathProg model processing error
>
> ########
>
> Anybody knows how to do this set of constraint properly in MathProg properly?
>
> Any suggestions?
>
> Thanks.
>
> Regards,
>
> Noli
>
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