[Gnuplot-info] voigt function fitting

[Andres C. <aci...@gm...>]

Dear gnuplotters,

I'm trying to fit a voigt profile to a spectrum. The voigt profile is
defined as the convolution of a gaussian with a lorentzian (or
alternatively the real part of the complex error function with
argument x + i*gamma, where gamma is the lorentzian width. All divided
by sigma - the gaussian width).

My labmate has always used matlab for fitting spectra, but always
gaussians. I tried a few things in Matlab but they didn't quite work.
I've used gnuplot to fit spectra (only gaussians again) and it has
worked very well, but I don't know how to do voigt profiles in it.

A quick google search "gnuplot voigt"  has this as first hit:

https://sourceforge.net/tracker/?func=detail&aid=2935103&group_id=2055&atid=302055

Which states there was a commit, back in January, to gnuplot to
implement a voigt function. But I've tried typing 'help voigt' and I
get nothing in the gnuplot CLI.

I'm using gnuplot 4.4.0 as shipped with Debian Squeeze (testing). So
was this code commit accepted for version 4.4.x or should I be looking
at 4.5.x to see this new feature implemented?

In any case, I still need to do the fitting, so anyone has any
experience with this and could point out some help?

Thanks a lot in advance

Andres