Re: a problem about NDSolve and NIntegrate
- To: mathgroup at smc.vnet.net
- Subject: [mg80142] Re: a problem about NDSolve and NIntegrate
- From: lynn <lynn0701 at gmail.com>
- Date: Mon, 13 Aug 2007 04:41:35 -0400 (EDT)
- References: <f9emog$lpq$1@smc.vnet.net>
On 8 9 , 5 28 , lynn <lynn0... at gmail.com> wrote:
> Hello,
>
> I'm tring to solve a diffrential equation with
>
> its upper boundary as a variable.
>
> and then I want to integrate it, and define
>
> it as a funcion with two variable.
>
> However, I don't know why it doesn't work at the second step.
>
> my equation is as following,
>
> f[c_?NumberQ]:=y[x]/.NDSolve[{eqn,y[0]==1,y'[0]==0},y,{x,0,c},M=
axSteps-
>
> >10000][[1]]
>
> n[w_NumberQ,c_NumberQ]:=NIntegrate[c*y[x]*(r-w)],{r,w,1}]
>
> function f works well, however there's some problem in funcion n,
>
> and it's confused me for a long time...,
>
> thanks for your help!!
>
> Best Regards!!Lynn
Thanks for your pointing out my faults.
I miss-typed it when I tried to simplize my equation.
But my original problem still exist,
The following is the original equation,
f[ _?NumberQ] := y[ ] /. NDSolve[{
2 y'[ ] y[ ] +
y''[ ] y[ ] -
(y'[ ])^2 == y[ ], y[0.00001] == 1, y'[0.00001] == =
0}, y,
{ ,
0.00001, }, MaxSteps -> 1000][[1]]
then f[5]=InterpolatingFunction[{{0.00001, 5.}}, <>][ ]
and I want to integrate it y[ ] with a ,
\!\(g[w_?NumberQ, _?NumberQ] := 2\
NIntegrate[\ \/y[ ]=D7 \/\@\( \^2 - w\^2\), { , w, },
MaxRecursion -> \
10]\)
But I can't get correct answer when ask for such as g[1,2]...
Thanks a lot!!
Sincerely, Lynn