Group: Mathematical Functions
Subgroup: Fourier and Wavelet transforms
See also: fft

Function: invfft
Description: invfft computes the Inverse Fast Fourier Transformation of a complex vector.

Usage: y = invfft (x)
Input:
x p x 2 matrix
Output:
y p x 2 matrix

Notes:
In the input matrix the first column is the real part of the vector and the second column the imaginary part.
In the output matrix the first column is the real part of the transformed vector and the second column the imaginary part.
p must be an integer power of 2.

Example:
randomize(0) 
x = normal(4) 
y = #(0,0,0,0) 
z=fft(x~y) 
invfft(z) 

Result:
[1,] -0.21293     0 
[2,] -1.0078 -9.9048e-17 
[3,] 1.9502     0 
[4,] -1.3052 9.9048e-17 






Group: Mathematical Functions
Subgroup: Fourier and Wavelet transforms
See also: fft

© XploRe, generated on 6.3.98 7:17 .