FFT v0.1.1 FFT View Source
FFT - Fast Fourier Transform Algorithm for fast fourier transform, which is widely used in the treatment of signals.
The fast fourier transform picks up the signal input in a given time period and divides it into its frequency components.
Link to this section Summary
Functions
Bit-reverse. List -> List input a list and returns a list with the reassembled elements using bit-reverse
Transform
Link to this section Functions
Bit-reverse. List -> List input a list and returns a list with the reassembled elements using bit-reverse.
Example
iex> a = [0, 1, 2, 3, 4, 5, 6, 7]
[0, 1, 2, 3, 4, 5, 6, 7]
iex> FFT.bit_reverse a
[0, 4, 2, 6, 1, 5, 3, 7]
Transform
List (With length power of 2) -> Complex List
Input list and return the fft-list.
Example
iex> a = [1,1,1,1,0,0,0,0]
[1, 1, 1, 1, 0, 0, 0, 0]
iex> FFT.transform a
[#ComplexNum (Cartesian) <4.0 + 0.0ยท๐>,
#ComplexNum (Cartesian) <1.0 + -2.414213562373095ยท๐>,
#ComplexNum (Cartesian) <0.0 + 0.0ยท๐>,
#ComplexNum (Cartesian) <1.0 + -0.4142135623730949ยท๐>,
#ComplexNum (Cartesian) <0.0 + 0.0ยท๐>,
#ComplexNum (Cartesian) <0.9999999999999999 + 0.4142135623730949ยท๐>,
#ComplexNum (Cartesian) <0.0 + 0.0ยท๐>,
#ComplexNum (Cartesian) <0.9999999999999997 + 2.414213562373095ยท๐>]