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List:       kde-devel
Subject:    Re: First Announcement Of KMathCenter
From:       Christian Parpart <cparpart () surakware ! net>
Date:       2002-04-30 18:34:22
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Chris January inspired the electrons to say:
> > Hi all,
> >
> > KMathCenter is a math science application wich intents to go
> > into the kde-edu package set.
> >
> > The current features of KMathCenter are:
> > * symbolic derivations
> > * symbolic expression simplifications
> > * string based expression calculation.
> > * analytic function plotter
> >
> > The current features goals are as follows:
> > * symbolic expression integration
> > * symbolic expression expanding
> >    * everything else you need to compute a complete curve
> >   discussion (I unfortunately can't say these things in
> >   english)
> > * scripting system for advanced mathematical algorithms
> >
> > KMathCenter has also some requirements:
> > * KDE 3 (of course :o)
> > * OpenGL (at least MesaGL, software driven - www.mesa3d.org)
> >   (you'll also need its developer include headers gl.h and glu.h)
> > * libmath++ (is bundled into the package)
> > * ISO/ANSI C++ compliant compiler
> >   (that's mostly gcc3, for gcc2 exists a source level fallback,
> >   so it'll work there too)
> >
> > Screenshots of KMathCenter made while coding on it are available at:
> > http://www.surakware.net/projects/kmathcenter/shots.xml
>
> From the screenshots:
> Eh?
> If f(x) = x ^2
> Then f'(x) != x^23*24

Okay, I found just one screenshot having a x^2 to be derived.

[x^2]' = x^24*(0*ln(x) + 1*24/x)

You must note that this is a common derivation rule for f(x) ^ g(x)
wich isn't yet simplified. This screenshot is an older state, expression 
simplification is now implemented.

So, lets have a look more into:

the common rule for f ^ g, where f = f(x) and g = g(x) is:

	[f ^ g]' = f ^ g * (g' * ln(f) + (f' * g) / f)

applied to x^2 as follows:
	  x ^ 2 
	= x ^ 2 * (0 * ln(x) + (1 * 2) / x)
	= x ^ 2 * (0 + 2/x)
	= 2*x

Now a look to the screenshot we had lets me remember that I previously had a 
bug in parsing numbers (I must have parsed someing like 14 before) wich 
didn't erased the previous number string completely :( it's solved now :)

So, I feel sorry about that little bug, it has been a mistake to make a 
screenshot of it, I'm going to replace it with a better derivation screenshot 
:)

> Regards
> Chris

Christian Parpart
http://www.surakware.net
 
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