Re: Some way to differentiate (1st order derivative)?

[<HBB...@t-...>]

Levente Novák wrote:
> AFAIK calculating or approximating the 1st order derivative of a
> function or x-y dataset was not (easily?) possible a few years ago from
> within gnuplot, but maybe this has changed since then 

It hasn't.  Numeric differentiation (and integration, and lots of other 
sides) is on the wrong side of the boundary between plotting and data 
processing.

> But afterwards, I need the 1st order
> derivative of the fitted or smoothed curve.

For the fitted curve, that should be reasonably easy.  Derive it 
algebraically (you know --- that thing you do with pencil, paper and 
scratching your skull), then have gnuplot plug in the fitted parameters 
and plot it.

> If not, is it still possible to perform differentiation from within
> gnuplot (even if this means using some awk script or similar), as I
> would like to automate the process and gnuplot is easily driven from
> a shell script or batch file.

Nothing changed in that area, either.

	plot "< myscript datafile"

works just as well as it always did.