Re: NIntegrate
- To: mathgroup at smc.vnet.net
- Subject: [mg36521] Re: NIntegrate
- From: Alois Steindl <Alois.Steindl at jet2web.cc>
- Date: Wed, 11 Sep 2002 03:27:38 -0400 (EDT)
- Organization: Inst. f. Mechanics II, TU Vienna
- References: <alkhi3$ve$1@smc.vnet.net>
- Sender: owner-wri-mathgroup at wolfram.com
"Rob_jack" <rob_jackNSP at libero.it> writes:
> Hello!
>
> I've this problem with NIntegrate:
> **********************************************
> In[1]=f[y_,z_]: = (y^4/( (1+(8.44*10^-4)^2 * (1+z)^2 y^2) (Exp[z]+1) )
>
> In[2]=F[z_]: = NIntegrate[f[y,z], {z, 0, Infinity}
> **********************************************
>
> Mathematica 4.0 says:
>
> ****************************************************************************
> *
> NIntegrate: : inum : Integrand 1.07577/( 1+7.12336*10^-7 (1. + z)^2 ) is not
> numerical at {y}={1.}.
> ****************************************************************************
> **
>
> What is it??
>
Hello,
I doubt that you could input your equations as you stated:
The first input has a missing )
The second one a missing ]
In both equations there should be no space in :=
Apart from that the second definitions doesn't seem to make much
sense, maybe it should be F[y_] := ...
Have you assigned y some value before (I get a different error
message, when I mix up the y and z as you did.)
Good luck
Alois
--
Alois Steindl, Tel.: +43 (1) 58801 / 32558
Inst. for Mechanics II, Fax.: +43 (1) 58801 / 32598
Vienna University of Technology,
A-1040 Wiedner Hauptstr. 8-10