% coswave.m - Generates a cosine wave: 8000 samples, 1 s, 200 Hz
% (when played at 8000 samples/s)

  length = 8000;
  freq = 0.025;                % i.e. 200 Hz / 8000 Hz
  arg = 2 * pi * freq;

Out = round(32000 * cos(1:length * arg));

% SIGNAL_OUT.M
% Write a signal in variable "Out" to a raw binary file

file_out = input('Please enter the name of the output signal file: ','s');
fid_out = fopen(file_out,'w');
fwrite(fid_out,Out,'integer*2');
status = fclose(fid_out);

% Convert a raw binary signal to a wav file
unix('sox -r 8000 -b 16 -e signed-integer -c 1 cosine.raw cosine.wav')

% ALTERNATIVELY
% wavwrite (y, fs, nbits, filename)

wavwrite (Out, 16000, 16, 'cosine.wav')