Peak Detection with Base package

Question

Hello,
I'm constrained by a budget so I can't purchase the analysis package
just for peak detection. Does anyone have any hints on how to search a
1-D array for peaks without using the pre-made VI's? I've been pulling
my hair out over this one for a week!
Thanks in advance.

Answer 1

Labviewguru wrote in message news:<[email protected]>...
> Jason,
>
> I would suggest looking online for a "peak detection" algorithm.
> There are a number of ways to do it. The LabVIEW peak detector using
> a least squares quadratic fit to find the peaks, with a filter of
> amplitude and width. This can also be done much simpler ways. You
> can try applying a smoothing filter (use a moving or windowed average)
> and then look for peaks that way.
>
> Please post if you need more assistance. Also, what are you trying to
> do with the peak detection. This would be helpful in providing
> further assistance.
>
> Good luck
Labviewguru
Thanks for the advice. Yeah, the NI home page tells me that th
ey use a
least square quadratic fit to find the peaks. I'm not sure on how to
implement that. I'll do a web search on that one. I'm not dealing with
a very noisy signal so I don't think that I need to do a moving
average. The amplitude filter seems pretty easy, I just compare each
point to a preset threshold. However my peaks are composed of more
than one sample so each peak gives me a bunch of "true" values. I only
want one count per peak. The way I thought of doing it was using
hysteresis and starting a subroutine when the upper limit boolean went
hi, then resetting the subroutine when the lower limit boolean went
hi. So essentially i need to have labview look for a high, THEN look
for a low, THEN reset over and over again until the sample array is
finished. I'd love to work on this for days but I've already put too
much thought into it.