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## Gaussian peak Fit FWHM

Hi

I am using the Gaussian Peak Fit Vi and I want to calculate the FWHM of the fitted curve. What is the best way to do this. Thanks

Message 1 of 6
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## Re: Gaussian peak Fit FWHM

Hi Zepp

I'm not too familiar with the Gaussian function, however after some quick research I've seen that the:

FWHM = 2 * (sqrt (2*ln 2)) * C

Where I believe C is the centre.

To build this you can either use a math script node or build it using the correct function blocks. I've attached a VI and VI snippet that uses both of these methods. I haven’t wired up the inputs of the Gaussian Function as I am quite unfamiliar with it.

Let me know if this is what you were looking for.

Many thanks.

Dan

Daniel Harryman MEng
CLA, CPI
Message 2 of 6
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## Re: Gaussian peak Fit FWHM

C here is the standard deviation

Message 3 of 6
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## Re: Gaussian peak Fit FWHM

Almost correct: C is not the center, it is standard deviation.

PS. for single variable, single line formulas it is better to use expression node.

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## Re: Gaussian peak Fit FWHM

If you search for FWHM Gaussian, you can find that the Full Width at Half Maximum (which "answer analysis" should tell you will be related to the Standard Deviation, usually expressed as a lower-case sigma, σ, is

Bob Schor

Message 5 of 6
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## Re: Gaussian peak Fit FWHM

Hi Alexander,

I appreciate the feedback. Silly mistake on my part.  Kind of makes me want to go back and check a few of my older forum posts and see if I'm any wiser now or just older haha.

Thanks,

Daniel

Daniel Harryman

Certified LabVIEW Devloper

Electronics Engineer

ISIS Neutron & Muon Source

Accelerator Diagnostics Development

Science & Technology Facilities Council

Rutherford Appleton Laboratory

Daniel Harryman MEng
CLA, CPI
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