Module: Cowboy

Defined in:
lib/cowboy.rb,
lib/cowboy/fft.rb,
lib/cowboy/version.rb,
ext/cowboy/cowboy.c

Defined Under Namespace

Classes: CowboyArray, Frequencies, Hamming

Constant Summary collapse

VERSION = 
"0.0.2"

Class Method Summary collapse

Class Method Details

.fft(arr, w = Hamming, n = 29) ⇒ Object 



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# File 'lib/cowboy/fft.rb', line 34

def Cowboy::fft(arr, w=Hamming, n=29)
  if !w.nil?
    window = w.new(n)
    input = window.convolve(arr)
    fft_1d(input)
  else
    fft_1d(arr)
  end
end

.fft_1d(v) ⇒ Object 



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# File 'ext/cowboy/cowboy.c', line 5

VALUE fft_1d(VALUE m, VALUE v) {
  fftw_complex *in, *out;
  fftw_plan fp;
  int n;

  n = (int) size_of_val(v);
  if (n == 0) {
    rb_raise(rb_eException, "Can't use empty set of samples");
  }

  in = allocate_fftw_complex(n);
  out = allocate_fftw_complex(n);
  fp = fftw_plan_dft_1d(n, in, out, FFTW_FORWARD, FFTW_ESTIMATE);

  cast_val_to_complex(in, v);

  fftw_execute(fp);
  free(in);
  fftw_destroy_plan(fp);

  return ca_wrap_struct_class(out, n);
}