Data Comparison

[adarshn1192]

Hello 

I have simulated a sine wave using the 'simulate signal' block and stored ther resulting waveform as a TDMS file. 

When I read the file and compare it with the generated sine wave of similar properties, I expect a constant true(LED) output.

Eventhough the probes show similar values under highlight, on comparison the 'equal' comparator does not give a consistent 'true' output.

Thanks 

[Sam_Sharp]

Have you tried comparing just the Y-values from the waveform? A waveform contains a t0 timestamp which will differ depending on when the waveform was started/saved so that might be why it's not showing as equal. Also, is there possibility in your code for the sine waves to become out of phase?

[Norbert_B]

Also keep in mind that it is a real bad idea to compare floating point numbers by equal. You should compare the waveform to an envelope function.

Norbert

[Sam_Sharp]

Norbert - I agree with you (if you have data from two different sources - a DBL of 0 doesn't always equal (bitwise) another 0) but in this case I would have hoped that the sine wave function to generate exactly the same values in both cases (assuming the parameters are the same)

[Norbert_B]

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@Sam_Sharp wrote:

[...] (assuming the parameters are the same)

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That might be true for this instance, yes, but we urge for generic solutions, do we? 😉

Norbert