Simple FFT example

[ninskaya]

Hi, I am looking for a simple FFT example in order to display a time domain graph into a frequency domain graph. I am wondering if the below vi goes in the right direction.

Thanks,
Ninskaya

[johnsold]

Ninskaya,
You are on the right track. You need to determine the X-axis (frequency) and create an array to display it in the Waveform Graph. An alternative approach, probably easier, is to use Analyze>>Waveform Measurements>>FFT Spectrum.vi.

[ninskaya]

Hi Johnsold, Thanks a lot for your answer. I first tried to use the FFT Spectrum.vi but I could not find out how to convert the arrays into a waveform that goes that vi. Could you tell me how to do it?

Bye,
Ninskaya

[Dennis_Knutson]

On the Waveform palette is the Build Waveform function. There are three possible inputs, Y (a 1D array of data points), t0 (start time), and dt (sample rate). You can drag the function to see the inputs or right click on it and choose Select Item or Add Element just like a Bundle by Name. For your FFT, you need to wire in at least the array and dt value.

[ninskaya]

Thanks a lot.
Ninskaya