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Help with NMinimize of NIntegrate function

  • To: mathgroup at smc.vnet.net
  • Subject: [mg85538] Help with NMinimize of NIntegrate function
  • From: vasil michev <michev at gmail.com>
  • Date: Wed, 13 Feb 2008 04:25:37 -0500 (EST)

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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