Calculates the Inverse Fast Fourier Transform of a series or series expression with the result in Cartesian (Real/Imaginary) form.
IFFT(series)
series |
- |
A series or array. |
A complex series or table in Cartesian form.
W1: 1..5
W2: fft(w1)
W3: real(ifft(W2))
W3 contains the series {1, 2, 3, 4, 5}.
FFT and IFFT implement the discrete Fourier transform pair X[k] and x[n] for series x of length N and start index 1 by:
A mixed radix algorithm is employed to compute the IFFT, however series with lengths that are a power of 2 will be processed faster than other series. Use the LENGTH function to find out if a series is a power of 2 points long.
Use IFFTP to get magnitude/phase output.
IFFT returns a complex result. Use REAL to obtain the real part.
See DADiSP/FFTXL to optimize the IFFT computation.
Oppenheim and Schafer.
Digital Signal Processing
Prentice Hall, 1975
Digital Signal Processing Committee
Programs for Digital Signal Processing
I.E.E.E. Press, 1979