Full Width at Half Max (FWHM) of a peak in JMPFWHM was a common calculation I had to do in my former life on X-ray diffraction. I had a customer ask if this is doable in JMP. I know of a way that is not pretty where you find a maximum using summary statistics then you can get to the answer with a bit of hand calculation. I saw this same question on the community without an answer I wanted to check to see if anyone know of a more elegant way to do this kind of calculation in JMP?
Re: Full Width at Half Max (FWHM) of a peak in JMPSASfit! Yikes! Haven't seen that for a while. Some labmates used that. I just used Fityk (http://fityk.nieto.pl). I really hope that FDE will incorporate the functionality these other packages have. It's so close already.
MRe: Full Width at Half Max (FWHM) of a peak in JMPThanks Brady and Mike,
I think this will get him started. I also agree with Mike that the Voigt fit would be great.
http://sasfit.ingobressler.net/manual/Voigt
Re: Full Width at Half Max (FWHM) of a peak in JMPPeter, something like this might work, depending on the shape of the curve, and if FWHM is as illustrated in the picture here:
https://en.wikipedia.org/wiki/Full_width_at_half_maximum
Names Default To Here(1);
//set up epsilon
e = 0.01;
//use a sample x and y
x = (0::6.28::.01)`;
y = cos(x)+1;
//find fwhm
hm = min(y) + (max(y)-min(y))/2;
xvals = x[loc(hm-e <= y <= hm+e)];
fwhm = max(xvals) - min(xvals);
Re: Full Width at Half Max (FWHM) of a peak in JMPIt probably should be in there as part of Fit Curve, but it’s not. With XRD, you’re also missing some of the important peak shapes (Voigt for example). I think your best bet is the hack using summary stats or fit curve. Or if you want to get fancy, you could create a custom function (using the FWHM) and then fit it that way using Nonlinear.
M
