i posted my patch earlier, but maybe nobody could bother to get it to work, so here it is, it does it all by itself, just check it out and tell me why it is clicking at the end of each cycle of the sine wave, sounds like its off by a few samples and is producing clicks.
the other little part with the metronome and the line~ object makes it produce a non-clicking waveform readback, but the thing is that clearly a wave reading ti back and not a line~ object is infinitely better.