Date: Sep 21, 2013 4:19 AM
Author: Murray Eisenberg
Subject: Re: plotting integrals
Perhaps trying to evaluate the integrand at one particular value will give a clue to what's wrong:

Subscript[\[Eta], B][0, 1, 3]

NIntegrate::itraw : Raw object 0 cannot be used as an iterator

Sqrt[1 - NIntegrate[\[Psi]1[0, 1, 3]*\[Psi][0, 1*Sqrt[2*3*(3 - 1)]], {0, -Pi/2, Pi/2}]]

You're trying to integrate a function of "variable" that's actually the constant 0 !

On Sep 20, 2013, at 7:07 AM, Herman <btta2010@gmail.com> wrote:

> Dear All,

>

> I would like to plot the function Subscript[\[Eta], B] but I got errors.

> Could someone please help me with these errors?

>

>

> \[Psi][x_, \[Omega]_] := (\[Omega]/\[Pi])^(1/4)

> Exp[-1/2 \[Omega] x^2]

>

> \[Psi]1[x_, a_, n_] := Sqrt[(2 n)!!/((2 n - 1)!! \[Pi])] Cos [a*x]^n

>

> Subscript[F, TPT][x_, a_, n_] :=

> NIntegrate[\[Psi]1[x, a, n]*\[Psi][x,

> a*Sqrt[2 n (n - 1)]], {x, -\[Pi]/2, \[Pi]/2}]

>

> Subscript[\[Eta], B][x_, a_,

> n_] := Sqrt[(1 - Subscript[F, TPT][x, a, n])]

>

> Plot[Subscript[\[Eta], B][x, 1, 3], {x, -\[Pi]/2, \[Pi]/2}]

---

Murray Eisenberg murray@math.umass.edu

Mathematics & Statistics Dept.

Lederle Graduate Research Tower

University of Massachusetts

710 North Pleasant Street

Amherst, MA 01003-9305