Re: plotting the derivative of a splined/interpolated function
- To: mathgroup at smc.vnet.net
- Subject: [mg50758] Re: [mg50682] plotting the derivative of a splined/interpolated function
- From: "David Annetts" <davidannetts at ihug.com.au>
- Date: Sun, 19 Sep 2004 21:39:14 -0400 (EDT)
- Sender: owner-wri-mathgroup at wolfram.com
Hi Todd,
> BUT I can't seem to plot either dervie or dervie2 with the standard
> Plot ParametricPlot commands
>
> So the question becomes is, how to I plot the derrivative of an
> interpolated or slpined function?
data = Table[{t, Sin[2 Pi t / 128]}, {t, 0, 128, .5}];
dint = Interpolation[data];
Plot[{dint[t], dint'[t]}, {t, 0, 128}, PlotStyle -> {Red, Black}];
Plot[{dint[t], dint''[t]}, {t, 0, 128}, PlotStyle -> {Red, Black}];
Works fine for me.
With regard to differentiating splines, I'd suggest interpolating the
spline, then differentiating the interpolant as above.
Regards,
Dave.