fourier transform of sine wave and square wave not returning the frequency of the wave.

[mp91]

Hi all, 

I've made some programs to see the Fourier Transforms of Sine Waves and Square waves. I understand that square waves should have harmonics when FTed but the Harmons of the square wave isn't coming out at the right frequency and neither is the sine wave. Any help would be appreciated. I've attached my programs so you can take a look. 

Thanks much, 

M

[johnsold · Accepted solution]

Your frequency axis VI is missing.

Since the data is uniformly sampled you can use a regualr graph rather than the XY Graph. Then you do not need to create an X-axis array. Use a property node to set the frequency axis scale multiplier and offset.

Lynn

[mp91]

Thanks, this helped lots.