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Re: Help with NMinimize of NIntegrate function

  • To: mathgroup at smc.vnet.net
  • Subject: [mg86762] Re: Help with NMinimize of NIntegrate function
  • From: antononcube <antononcube at gmail.com>
  • Date: Thu, 20 Mar 2008 02:55:49 -0500 (EST)
  • References: <fouedm$m7f$1@smc.vnet.net>

The definition of the function EAa is wrong. Instead of

EAa[t, J, m, Q3, Q2]:= ...

it should be

EAa[t_, J_, m_, Q3_, Q2_]:=...

Then you won't get the NIntegrate::inumr messages.

Anton Antonov
Wolfram Research, Inc.


On Feb 13, 5:48 am, vasil michev <mic... at gmail.com> wrote:
> What's wrong with this code:
>
> test[t_?NumericQ, J_?NumericQ,
>   m_?NumericQ, (Q3_)?NumericQ, (Q2_)?NumericQ] :=
>  NIntegrate[
>     EAa[t, J, m, Q3, Q2]*
>      HeavisideTheta[EAa[t, J, m, Q3, Q2]], {x, -Pi, Pi}, {y, -Pi,
>      Pi}, {z, -Pi, Pi}, MaxPoints -> 1000000,
>     Method -> "LocalAdaptive"]/8/(Pi^3)
>
> In[75]:= test[10, 1, 1, 1, 1] // Timing
>
> Out[75]= {5.819, 2.22142}
>
> where
> EAa[t, J, m, Q3, Q2]:= 1/2 (-3 J - 2 m - 2 t (Cos[x] + Cos[y]) -
>     2 t (Cos[x]/3 + Cos[y]/3 + (4 Cos[z])/3)) -
>  1/2 Sqrt[16 (-(Q2/2) - (t Cos[x])/Sqrt[3] + (t Cos[y])/Sqrt[
>       3])^2 + (-2 Q3 + 2 t (Cos[x] + Cos[y]) -
>      2 t (Cos[x]/3 + Cos[y]/3 + (4 Cos[z])/3))^2]
>
> with
> NMinimize[test[10, 1, \[Mu], q, Q], {\[Mu], q, Q}]
> I get those inumr errors, have i set anything wrong? Everything should
> be numerical, x,y,z are integrated out, so what is it?



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