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Constraint definition is not valid: WHY?

• To: mathgroup at smc.vnet.net
• Subject: [mg131358] Constraint definition is not valid: WHY?
• From: aless.bolli at gmail.com
• Date: Mon, 1 Jul 2013 05:48:38 -0400 (EDT)
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I am tring to use Nmaximize in Mathematica This is How I proceeded:

1) define a list of parameters: Par = {a->1, b->3, etc};

2) define two functions: f1: v1=express./Par f2: v2=express./Par

After this the expression are numerical except for the variables:

V1=f(e1,x) and V2=f(e2,x)
The objective function to be maximized is V1/(e1+e2) I defined the constraint as constr=V1-V2;

then I used the Nmaximize:

 NMaximize[{objopt > 0, constr == 0}, {e1, e2, x}, Method -> NelderMead]
I obtained the following error:

NMaximize::bcons: "The following constraints are not valid: "expression". Constraints should be equalities, inequalities, or domain specifications involving the variables"

I checked that only those variables are present in the constraint and objective function (other are numerical parameters) I do not understand why this error appears can someone help me?

Thank you

Alex

• Follow-Ups:
  • Re: Constraint definition is not valid: WHY?
    • From: Bob Hanlon <hanlonr357@gmail.com>