how to find the maxima and minima of a sawtooth wave form

[bdcpp08]

Hi,

I am getting a problem in my programme and please help me to find out the solution. I have my experimental data in an excel spreadsheet and on plotting these data, it nearly gives a sawtooth waveform. Now I want to find out all the local maxima and minima points of the waveform. Then I want to extract all the data points between each local maxima and minima. For better understanding my problem I have paste a diagram.

Regards

bdcpp08

[P@Anand]

Did you try Peak Detection VI?

[NIquist]

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P@Anand wrote:

Did you try Peak Detection VI?

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Look at the example called Peak Detection and Display.vi to get started.  I does half of what you need already.  

[P@Anand]

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@NIquist wrote:

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P@Anand wrote:

Did you try Peak Detection VI?

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Look at the example called Peak Detection and Display.vi to get started.  I does half of what you need already.  

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You really meant to quote me? 

[AnalogKid2DigitalMan]

2x Niquist sampling theorem fulfilled 🙂

-AK2DM

[NIquist]

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P@Anand wrote:

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@NIquist wrote:

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P@Anand wrote:

Did you try Peak Detection VI?

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Look at the example called Peak Detection and Display.vi to get started.  I does half of what you need already.  

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You really meant to quote me? 

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Well... Yes, why wouldn't I?  You DID just mention the Peak Detection VI and I was elaborating on its use.  See the connection? 

[P@Anand]

I got it:)

[bdcpp08]

Hi 

thanks all for suggesting to my post. But the peak detection vi gives the peak amplitude corresponding to the index value. I want to find out the peak position corresponding to time and to extract the data points between the peaks and the valleys. can you give some hints regarding to this problem.

Thanks again.

[NIquist]

You can do the math to convert from index to time easily.  A waveform consists of a T0 (start time), dT (delta T or time between points) and an array of Y values.  T get real time multiply dT * # of samples (data point) and add it to the T0.  Look at Waveform Get Time Array in the Waveform palette, that's what it does.