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List:       kde-core-devel
Subject:    Re: Need help for KSpread Maths
From:       Stephan Kulow <coolo () kde ! org>
Date:       1999-11-18 10:16:44
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Cristian Tibirna wrote:
> 
> On Wed, 17 Nov 1999, weis wrote:
> 
> > Hi,
> >
> > Excel has this "Goal Seek". Nice thing. You point it to a formular
> > and to the cell that is used as input and Excel finds the
> > input value that makes the formula result in a user specified value.
> >
> > In fact that is the problem of finding x in f(x) = 0.
> >
> > There are many algorithms which help you here, but they want
> > a) a range [a,b] to search in which can be very big with double values.
> > b) two points a and b, so that f(a)*f(b) < 0.
> >
> > Can anyone tell me what to do here. Excel is getting quick and good
> > results, so there must be a way.
> >
> > Bye
> > Torben
> >
> > PS: No algebraic solutions.
> 
> Seems like this is a job for me.
> 
> Torben, is this pressing? I have to fix kikbd first, and work on kwin in
> the meanwhile. But I'd really like to do this numeric kind of things since
> this is my real-life job: numerical simulation. I believe for more general
> situations a Simplex algorithm will do.
> 
> If it is very important to avoid local optimums, we can look at Simulated
> Anealing.
> 
Simulated Anealing is very powerful, but not _very_ fast. I'd like to
see
an implentation to judge outside of Matlab though :)

Greetings, Stephan

-- 
When your memory goes, forget it!

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