I've been wondering about this for years. When I try to use the sine opcode to create waveforms, I run into two glitches. The basic csd (complete csd attached) below should generate a nice, 200 seconds long, sinewave with a frequency of 4000/(2pi)=636.619... hz.
This works for the first 4 seconds of the output file. Then the pitch rises about 1% and remains there until 126 seconds in, at which point the pitch drops drastically to about 430 hz ( two-thirds?).
Anyone have any idea what's going on?