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DADiSP Worksheet Functions > Function Categories > Fourier Transforms and Signal Processing > IFFTP

 

IFFTP

Purpose:

Calculates the Inverse Fast Fourier Transform of a series with the result in polar (magnitude/phase) form.

Syntax:

IFFTP(series)

series

-

A series or array.

Returns:

A complex series or table in Polar form.

Example:

W1: gsin(128,0.01,1, 4)

W2: ifftp(W1)

 

displays the inverse Fourier Transform in magnitude and phase form.

 

W1: gsin(100,0.001,50, 0)

W2: fftp(W1)

W3: ifftp(W2)

 

returns a rectified waveform because the magnitude in W2 is always positive.

 

W4: ifft(W2)

 

returns a sine wave that looks like W1 because DADiSP first converts W2 to Cartesian coordinates then takes the IFFT.

Remarks:

Uses the same algorithm as the IFFT but is slower because it calculates magnitude/phase.

See Also:

FFT

FFTP

IFFT

References:

Oppenheim and Schafer.

Digital Signal Processing

Prentice Hall, 1975

 

Digital Signal Processing Committee

Programs for Digital Signal Processing

I.E.E.E. Press, 1979