How I can clip data?

[andpo]

Hi,

I am not an expert with LabView and with signal processing! I want to know if there is a function to 'clip' or 'extract' segments (windows) of data. I am using a sensor to measure feet pressure. The data contains peaks of the pressure but also many 'zero' data. For statistics, I want to recontruct my data and keep only the peak of pressure, that is erase all the zeros. I found some functions in LabView to extract data but is only working for the first peak, I can't takeand regroup all the peaks.
Thanks for the help.
Andres

[falkpl]

if your data is in an array you can do something as simple as fiid it into an auto index and do a case structure where if it is below a threshold (ie zero) bass an array strait through else append to another array using a shift register to store the clipped array.  I can post an example of this later today if needed.

[andpo]

Hi,

Thanks for your fast response! If you can send me an example it can be VERY useful!
Thanks again
Andres

[falkpl]

Here is a simple example, it essentailly does the same as threshold array but you can modify the logic to do any type of clipping you want (change the boolean to allow for hi/low bandpass or notch filters .....  There are many precanned functions to do such things but I like to know what is going on with my data without making any assumptions.

Paul

[unclebump]

If you are using the waveform datatype, here is a link to a vi that will clip the waveform at a value or replace with NaN. It will also invert the waveform if you want.

http://sine.ni.com/apps/we/niepd_web_display.DISPLAY_EPD4?p_guid=C44A74A456A8650DE034080020E74861&p_...=

[andpo]

Hi all,

Thanks for your responses (and the examples)! Now I know how to do it! With LabView the solution is always more simple that we initially imagine.
Andres