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Topic: plotting integrals
Replies: 4   Last Post: Sep 24, 2013 4:16 AM

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 Murray Eisenberg Posts: 2,105 Registered: 12/6/04
Re: plotting integrals
Posted: Sep 21, 2013 4:19 AM

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.
>
>
> \[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.
University of Massachusetts
710 North Pleasant Street
Amherst, MA 01003-9305

Date Subject Author
9/21/13 Bob Hanlon
9/21/13 Murray Eisenberg
9/21/13 Itai Seggev
9/24/13 Herman