Here the generated data has been transformed to the frequency domain. The data is Complex, so ScopeDSP automatically shows a two-sided spectrum. Since the data was generated mathematically, it is "ideal" except for very small calculation errors. ScopeDSP has clipped the dB values to at its (optional) clip value of -110 dB to keep the plot's automatic scaling from losing too much vertical resolution due to a few "very good apples". Of course, you can also scale the plot manually to avoid this problem.

Examination of the first part of ScopeDSP's Frequency List shows that the next lowest component is actually more than 150 dB below the fundamental:

See Data Statistics and A/D Performance Measurement, Part 4 for more information about the Frequency List.