Posted by saudepp@googlemail.com on 09/06/07 18:22

On Sep 6, 7:24 pm, shimmyshack <matt.fa...@gmail.com> wrote:
> On Sep 6, 4:01 pm, "saud...@googlemail.com" <saud...@googlemail.com>
> wrote:
>
>
>
> > Hi php pros,
>
> > I have an array containing n numbers and want to fit them to e.g. a
> > polynomial function f(x), x=1...n.
>
> > Is there a php script / library for doing that?
>
> > I basically wish to do curve fitting to my data array, directly in
> > php.
>
> > Ideal would be something like polyfit in MatLab.
> > One possibility would be to involve a c++ program doing the data
> > fitting. Export the array as a dump file from php, execute the
> > compiled c++ polynomial fitting file program calling the dump file and
> > saving the result, and then open the result file in php. Thats of
> > course not so elegant ...
>
> > Thanks for any help.
>
> > Best
>
> > -saudepp
>
> there are COM objects (sold) which you can invoke from within PHP,
> other than that, writing your own spline model seems a challenge just
> to avoid the inelegance of using an existing c++ program.
> dont reinvent the wheel eh!
> by f(x) do you mean a cubic polynomial?


Hi,

I meant with f(x) a polynomial of any order g.

I have done it now with an external c++.

Here's the current result:
http://www.kampfpapst.com/daxprognose/mod/kurs-prognose.php?dt=20
with order g=5.

Would be good to include other fitting methods like spline,
interpolation etc.
Do libraries exist for that in php? Or c++ ...?

Thanks -saudepp

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