[Kst] Ways to evaluate expressions...

George Staikos staikos at kde.org
Mon Nov 14 20:46:30 CET 2005


On Monday 14 November 2005 12:14, Brisset, Nicolas wrote:
> Hi,
>
> I was looking at how qtiplot does non-linear fitting (with gsl) to try
> and develop a kst plugin, and it actually uses a math parser lib which
> you may be interested in. It's at: http://muparser.sourceforge.net/
> I would like to avoid the dependence on that one (gsl should be enough),
> but I need to find out how to :
> - compute the value of an expression at a given point (with some
> numerical values assigned to the formal parameters being fitted)
> - compute the (numerical) derivative of a function at a given point wrt
> to a given variable

  You can't with a data plugin yet.  We're going to make a new plugin model in 
the next release which will let you do that.  At best you can just copy the 
existing evaluator into your tree.  I have some ideas I want to experiment 
with in the evaluator to make it much faster yet, but that probably won't 
happen until the summer at the earliest.

-- 
George Staikos
KDE Developer				http://www.kde.org/
Staikos Computing Services Inc.		http://www.staikos.net/


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