Re: Ndsolve

• To: mathgroup at smc.vnet.net
• Subject: [mg84053] Re: Ndsolve
• From: "Kevin J. McCann" <kjm at KevinMcCann.com>
• Date: Fri, 7 Dec 2007 06:55:10 -0500 (EST)
• References: <fjauk0\$raa\$1@smc.vnet.net>

```NDSolve actually does generate an internal (x,y) table of numerical
values; however, it then continues on and calculates an
InterpolationFunction. The advantage of the latter is that you can take
derivatives, etc.

You might check the documentation on NDSolve.

Clear[y, Y]
Y = y /. First[NDSolve[{y'[x] == y[x], y[0] == 1}, y, {x, 0, 1}]]

You can check the BC:

Y[0]
1

Also
Plot[Y[x]-Y'[x],{x,0,1}]

Cheers,

Kevin

DrunkenButterfly wrote:
> I'm confused about the "interpolation" thing. Why if I have some diff eq with boundary conditions NdSolve doesn't give me a numerical solution? And suppose I have
>
> y'[x]== f[x]
> with y[a]== b as a condition (a,b any numbers)
>
> How can I find f[0], for example? (Generalizing, how can I find f[c], where c is a number?)
>
> Thanks to everyone! And please, help me :(
>

```

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