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Class: TFastFourier
Declaration: function FreqOfLine (ix: integer; SampleTime: double): double;

The function FreqOfLine calculates the line frequency of the spectral line with index ix (1 to SpectrumSize div 2), given that the sampling time is SampleTime seconds.

Please note that FreqOfLine is supposed to be used together with the properties Magnitude, PowerSpec, Phase, FourSerCosCoeff, RMS, and FourSerSinCoeff. When used with the indices of the array properties ImagSpec and RealSpec the parameter ix has to be incremented by one in order to obtain correct results (since the properties ImagSpec and RealSpec use a different indexing scheme).

Example: This method is used in the following example programs (see for downloading the code): fft60hz, fft

Last Update: 2012-Oct-20