Re: proposal for new m-file function

[Martin Helm]

Am 22.03.2012 10:43, schrieb Carlo de Falco:
>
>
> 2012/3/22 <address@hidden
> <mailto:address@hidden>>
>
>     Message: 2
>     Date: Wed, 21 Mar 2012 20:33:01 -0400
>     From: Ben Abbott <address@hidden <mailto:address@hidden>>
>     To: octave maintainers mailing list <address@hidden
>     <mailto:address@hidden>>
>     Subject: proposal for new m-file function
>     Message-ID: <address@hidden
>     <mailto:address@hidden>>
>     Content-Type: text/plain; charset="us-ascii"
>
>     A user's question about fixed points piecewise-linear fitting led
>     to the development of a function looks to be a good fit for
>     Octave's core.
>
>          
>      https://mailman.cae.wisc.edu/pipermail/help-octave/2012-March/050900.html
>
>     The idea was to fit a piece-wise polynomial to a set of data.
>     After some discussion between myself and Martin Helm, the attached
>     ppfit.m was produced. The name was chosen to match the existing
>     ppval().
>
>     The function provides a least-squares fit of a 1D interpolation
>     with specified break positions to a set of data.
>
>     Demos and tests are included.
>
>     Any concern about adding this to Octave's core ?
>
>     Ben
>
>
> googling for the name 'ppfit' I found this function:
>
> https://www.assembla.com/code/zaxxon_scripts/subversion/nodes/trunk/project/scripts/ppfit.m
>
> which seems to do the same as yours with the additional option of
> returning a spline with N continuous derivatives
> Would it be possible to add that option to your code?
> The license of the linked function looks like BSD so it should be no
> problem to get the code from there.
> c.
Wouldn't it be much cleaner to add that additional fitting options
(quadratics and higher order splines) to interp1 (without breaking
matlab compatibility of course)?
I think that is the place where such functionality should naturally
live. I could look at it over the weekend and propose a patch for it.