Gaussian fit of a peak

[Andrea Cimatoribus]

Hi everybody,
I am an absolute novice of octave, even though I have some experience
with matlab.
Just to get the feeling of octave, I am presently translating a simple
(but very useful to me) script, that basically sums data with a peak
structure. In order to do this properly, I need to centre each new
spectrum on the zero, that is the peak maximum. My strategy, in
matlab, was to make a preliminary gaussian fit, whose result was to be
confirmed through a graphical input, to get the "zero" of the
spectrum. As of now, I am trying to understand how can I make a
gaussian fit of the data in octave. Data is simply organised as a
matrix [x,y]. Is there a built function? Sorry but I can't find
anything with online help.
Andrea