Re: Numerical Differentiation
- To: mathgroup at smc.vnet.net
- Subject: [mg4291] Re: Numerical Differentiation
- From: Paul Abbott <paul at earwax.pd.uwa.edu.au>
- Date: Sat, 29 Jun 1996 03:55:33 -0400
- Organization: University of Western Australia
- Sender: owner-wri-mathgroup at wolfram.com
Mark James wrote:
> Does anyone know of a function that calculates the derivative of
> a function (that can't be differentiated symbolically)
Why can't it be differentiated symbolically?
> at a given
> point by numerical means? I can't find it as a built-in or in the
> standard packages. Thanks.
There is the ND function in NumericalMath`NLimit`.
Another way of proceeding is to sample the function at a number of
points, interpolate, and then differentiate:
points = Table[{x,f[x]}, {x,0,1,0.1}];
fint = Interpolate[points];
fint'[0.3]
This also works with partial derivatives (if you get the
DInterpolatingFunction.m package mentioned in the Mathematica Journal
4(2):31).
Cheers,
Paul
_________________________________________________________________
Paul Abbott
Department of Physics Phone: +61-9-380-2734
The University of Western Australia Fax: +61-9-380-1014
Nedlands WA 6907 paul at physics.uwa.edu.au
AUSTRALIA http://www.pd.uwa.edu.au/Paul
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