Matlab/Octave

Read an audio wav file and play it back:

[yy, fs] = audioread('f:/brad/projects/plutoSDR/logitechMike.wav');
 % assuming you've scaled yy to +/- 32000  
player = audioplayer(yy, fs, 16);  
 play(player) 

Polyfit:

[p,s] = polyfit(x,y,1)