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

[Ethan M. <merritt@u.washington.edu>]

On Tuesday 23 October 2007 13:01, ln...@dr... wrote:
> 
> My biggest problem for the moment is the following: I did not find anything
> useful about 'assignment' in the help file (I have the most recent CVS version
> of gnuplot, of course). How should I use it then? Is there a configure-time
> switch needed to compile it into gnuplot?

No, but it is a very recent feature.

Peter <pl...@pi...> referred to it as an "assignment feature" because
the original trial implementation was in the form of a separate function
named assign().  In the end, the same functionality was incorporated by
adding support for two standard operators:  =  and  ,
Both act as they do in the C language syntax.

'=' is an assignment operator, taking a variable name on the left and
an expression on the right.

',' is a serial evaluation operator separating independently evaluatied
expressions.

Combining these operators allows functions or expressions to have
side effects.  In particular, a function or expression evaluation can
have the side effect of storing its result in a named variable.

An example of using these to track successive data points is provided
in the new demo file data_feedback.dem
	http://gnuplot.sourceforge.net/demo_4.3/data_feedback.html



-- 
Ethan A Merritt            Courier Deliveries: 1959 NE Pacific
Dept of Biochemistry
Health Sciences Building
University of Washington - Seattle WA 98195-7742