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Re: Problem with NMinimize

  • To: mathgroup at smc.vnet.net
  • Subject: [mg91576] Re: [mg91549] Problem with NMinimize
  • From: Daniel Lichtblau <danl at wolfram.com>
  • Date: Thu, 28 Aug 2008 03:16:13 -0400 (EDT)
  • References: <200808271041.GAA20758@smc.vnet.net>

shama shahbaz wrote:
> i want to minimize the absolute value of this Equation
> e1=((0.0676+0.0067*I)*EXP[p1*I] )+(0.1633-0.0495*I)+(0.0676-0.0555*I)+((0.1633-0.3056*I)*EXP[p2*I]);
> e2=((0.1060-0.0708*I)*EXP[p1*I])+( 0.0708-0.1060*I)+( 0.0293-0.1474*I)+((-0.0439-0.2207*I)*EXP[p2*I]);
> e3=((0.0495-0.1633*I)*EXP[p1*I])+( -0.0067-0.0676*I)+( -0.0873-0.1633*I)+(( -0.0824-0.0676*I)*EXP[p2*I]);
> e4=((-0.0732-0.1768*I)*EXP[p1*I])+( 0*I)+( -0.1768-0.0732*I)+(( 0*I)*EXP[p2*I]);
> e5=((-0.1633-0.0873*I)*EXP[p1*I])+( 0.0676+0.0067*I)+( -0.1633+0.0495*I)+(( 0.0676-0.0555*I)*EXP[p2*I]);
>  
> c1=Abs[e1];
> c2=Abs[e2];
> c3=Abs[e3];
> c4=Abs[e4];
> c5=Abs[e5];
>  
>  
> Minimize[{(c1)2+(c2)2+(c3)2+(c4)^2 +(c5)^2,0=A3p1=A32*Pi,0=A3p2=A32*Pi},{p1,p2}]
>  
>  
> but it did not give me any answer
>  
> but i know that NMinimize can minimize the squared absolute value of the complex number as i have tried as following
>  
> q=(1.41*(Exp[Pi/4*I]+Exp[p*I]+1+Exp[p*I]*Exp[Pi*I/4]))^2;
> q1=(1.41*(Exp[Pi/5*I]+Exp[p1*I]+1+Exp[p1*I]*Exp[Pi/7*I]))^2;
> expression=Abs[q]+Abs[q1];
> NMinimize[{expression,0<p<2 Pi,0<p1<2 Pi},{p,p1}]
>  
> it gives me answer
>  
> {0.00453162,{p=AE3.14159,p1=AE3.23135}}
>  
> i dont know where i am wrong .....can some one point that out
>  
>  
> Regards

Mathematica is case sensitive.

I believe this has been mentioned, in one way or another, in earlier 
responses to what was essentially the same question from yourself.

Daniel Lichtblau
Wolfram Research


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