MPFX version of ExpModGauss

Hi all,

I'm creating a custom fitting routine using MultiPeakFit2. My fitting model uses exponentially modified Gauss line shapes to fit some spectroscopy data. The fitting is working fine, but I am running into problems getting the peaks out for display back to the user when I call MPFXEMGPeak.

If I execute the following code
make/o testcoefs={300,1,1,.5} //some typical seed coefficients

make/n=128 ywave  //create a y wave to have the shape
setscale /I x, 280,315,"units",ywave

duplicate/o ywave, xwave  //make an explicit x wave to match the dataset
xwave=x

display ywave vs xwave //plot the data

MPFXEMGPeak(testcoefs,ywave,xwave) //attempt to make an EMG out of the data


the last line appears to do nothing at all. No error message, no updating of the wave... just nothing.

If I instead execute
EMGPeak(testcoefs,ywave,xwave) //use the old-style EMG peak function

it appears to work.

Obviously MPFXEMGPeak must be working in some capacity, since it works in the multipeak fit package as distributed; why can't I make it work on its own?? I'm trying to make this routine as generic as possible so I don't want to hard code the old version because I'm looking up MPF results using peakfuncinfo calls.
I was able to make a plot of a MPFXEMGPeak, using your coefficients. Did you already have a peak in ywave? Is it possible that it worked, but just didn't look different?

Try
ywave = 0
MPFXEMGPeak(testcoefs,ywave,xwave)

If that doesn't make a visible difference (like, it remains a flat line) then we have a problem.

John Weeks
WaveMetrics, Inc.
support@wavemetrics.com
Hi John, thanks for listening.

ywave = 0
MPFXEMGPeak(testcoefs,ywave,xwave)

yields no peak. If I follow those commands with
ywave = 0
EMGPeak(testcoefs,ywave,xwave)

I get a peak as expected.

Some details: I am running v6.37 on MacOS 10.10.5 on a mid-2014 macbook pro with 16Gb RAM and an i7 processor at 3GHz.
I also have Igor 7.00B5 installed, but I find the display to be not super snappy on this machine so I'm not concentrating on adapting to it for now.

Is it possible that my v6.37 is somehow looking at a different MPFXOP because the beta is installed? Is it a Mac vs Windows compile issue?

EDIT: it works in beta 7! I guess I can use that for now.