I followed sin values for 22.5, 45, 67.5 and 90 degrees, multiplied by 127, obtained those 16 values :
0, 49, 90, 117, 127, 117, 90, 49,
0,-49, -90,-117,-127,-117,-90,-49
Hold trigs + Tempo for Interpolation (4 by 4)
You can set 2 values at the same time.
Btw, the graphic is not symmetrical.