FFT uncertainty

[payman]

Hello,

In the attached program, a series of frequencies is measured using Fourier Transformation. The slope of the measured frequencies vs the actual frequencies shows a linear relation but the slope is not exactly "1".

Could you please help me to understand why the slope is not exactly "1" ? Is the any analytic relation between the uncertainty and sampling specifications?

Thank you very much in advance.

Payman

[RichardJ · Accepted solution]

The denominator in the calculation of delta_x should be N0-1, not N0 (if you have N0 data points, you have N0-1 gaps between them).

[payman]

Thank you very much.