xy pairs to waveform

[Alex-at-work]

Hi,

I want to measure rise and fall times of scope/simulation data, which is saved as xy pairs.

I thought about creating a waveform and using the waveform measurement functions.

The issue is that the time step must be constant for creating a waveform. However, in my case the size of the time steps will change within one captured signal.

1) Is there any recommendation, how I can create a waveform out of xy pairs, where the size of the time steps changes?

2) Is it possible to determine rise and fall times directly from the xy pairs?

Thanks in advance for every hint!

Alex

[falkpl]

With non-uniform delta t incriments with f(t), t pairs you can always resample the signal.  Essentially to convert you find the least common delta t (the smallest time increment which is divisible by all times) and then interpolate the missing points f(t).  The waveform uses the interpolated and original f(t) array and the new dt and original t0 to build the waveform.  I am not sure if LV has such a vi in the standard library.

Paul

[Alex-at-work]

Hi Paul,

thanks for your idea. I will check, if I can implement this.

However, this sounds not that easy :-).

Alex

[falkpl]

There might be an easier method this what the first thing that came to mind, (it was 7AM and my caffeine gauge was on empty) .

Paul

[Alex-at-work]

Hi Paul,

I am still thinking about this. Let me know, if you get another great idea after the next coffee :-)!

Thanks,

Alex

[becktho]

Hi

This might help you. In LV8.0 there exist some nice interpolation vis.

But don't take it as example for coding style. 😉

Thomas

Message Edited by becktho on 07-21-2006 03:12 PM

[jasonhill]

To improve on beckto's example.  A little cleaner and you can select different interpolation methods.  (still requires 8.0)

Message Edited by jasonhill on 07-21-2006 08:17 AM

[becktho]

Jason, that's a good example for teamwork :D:D:D

Message Edited by becktho on 07-21-2006 03:19 PM

[Alex-at-work]

Thanks guys for your great support

I hope I can manage it to test your solution by today. You make me happy!

Alex

[jasonhill]

Great minds think alike.   I had just finished wiring up my example when you posted your.