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Algorithm used to calculate line centre in ISIS

Posted: Sat Nov 05, 2011 1:42 am
by Robin Leadbeater
What algorithm does ISIS use to calculate the wavelength of a line? It does not appear to use the barycentre or the median or a Gaussian fit.

Thanks
Robin

Re: Algorithm used to calculate line centre in ISIS

Posted: Thu Nov 10, 2011 11:36 pm
by Christian Buil
Hi Robin

ISIS use a multiparameter gaussien fit (FWHM, peak intensity, positition, background) for measure line profile.

Christian

Re: Algorithm used to calculate line centre in ISIS

Posted: Fri Nov 11, 2011 1:20 am
by Robin Leadbeater
Thanks Christian,

I tried ISIS again and this time the results were correct for a Gaussian fit. I am not sure why I got a different answer when I tried it before.

Robin