e.g. FftInTimeAmpl('Expression','Samples','#Freq','Min frequency'=0,'Max frequency'=Sampling/2,'Window'=0,'Overlap'=0,'SuppressDC'=FALSE,'ZeroPad'=TRUE)

Arguments

'Expression'	Signal or expression for which to calculate the Fourier transformation
'Time'	Determination of the time or length intervals used. This rounds to an interval containing 2^N samples.
'#Freq'	Number of frequencies displayed
'Min frequency'	Minimum frequency
'Max frequency'	Maximum frequency
'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

These functions calculate amplitude or power of the Fourier transformation of 'Expression' for sections with 2^N samples each. N is determined by rounding the product 'Time' × sampling frequency to a power of 2.

The result is a vector that contains '#Freq' equally divided frequencies between 'Min frequency' and 'Max frequency' per section. 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.

Example

You can use the FftInTime function to display fluctuating frequencies over time. The resulting vector can be displayed in a 2D view for this purpose.