gistfile1.txt

zetagun:~ corban$ ruby DFT.rb 200 square 1720Hz
                user     system      total        real
DFT:        0.050000   0.000000   0.050000 (  0.055424)

[DFT] 1720Hz squarewave / 44100.0Hz samplerate / 200 sample timesize
        .                                                                                           - 0.6
        .                                                                                           
        .                                                                                           - 0.5
        .                                                                                           
        .                                                                                           - 0.4
        .                                                                                           
       ..              .                                                                            - 0.2
       ..              .                                                                            
     .....           ....              .              ..              .                             - 0.1
     .....           ....              .              ..              .                             
----------------------------------------------------------------------------------------------------- 0.0
^       * ^         ^         ^         ^         ^         ^         ^         ^         ^         ^
0kHz     22kHz     44kHz     66kHz     88kHz     110kHz    132kHz    154kHz    176kHz    198kHz    221kHz