e.g. FftPeaksInTimeAmpl('Expression','Time','#Peaks','Min frequency'=0,'Max frequency'=Sampling/2,'Window'=0,'Overlap'=0,'SuppressDC'=FALSE,'ZeroPad'=FALSE)

Arguments

'Expression'

Signal or expression for which to evaluate the frequency spectra

'Time'

Determination of the time or length intervals used. This rounds to an interval containing 2^N samples.

'#Peaks'

Number of peaks displayed

'Min frequency'

Optional parameter for the minimally considered frequency, i.e. peaks at lower frequency are not shown

'Max frequency'

Optional parameter for the maximum considered frequency, i.e. peaks at higher frequency are not shown

'Window'

Window type: 0 = Square 1 = Bartlett 2 = Blackman 3 = Hamming 4 = Hanning 5 = Blackman-Harris 6 = Flat top

'Overlap'

Overlap factor

'SuppressDC'

DC suppression

'ZeroPad'

Adding zeros

Description

This function is used to calculate frequency peaks across smoothed time intervals, which are determined by the parameter 'Time'. In the process, the '#Peaks' are calculated, which are the highest peaks between the 'Min frequency' and 'Max frequency' frequencies. The timeline of the frequency and the pairs of peak values are returned as a vector.

The entries are sorted according to the following pattern:

  • Index 0: Frequency with the highest peak

  • Index 1: Amplitude/power of the highest peak

  • Index 2: Frequency with the second highest peak

  • Index 3: Amplitude/power of the second highest peak

  • Etc.

You can use the 'Window' parameter to set the window type that is used for the calculation. The overlap factor determines the overlapping of the time segments and can be between 0 (no overlap) and 1 (complete overlap). Optionally, you can activate DC suppression with the 'SuppressDC' parameter.

If the parameter 'ZeroPad' is set to 1 or TRUE(), the last window is filled with zeros before calculating the FFT. If 'ZeroPad'=False, the last window is discarded.