This quadrature oscillator might be useful for digital signal processing, graphics and anywhere you need to produce a sin/cos wave form more efficiently that actually calling the slow sin and cos functions:
https://groups.google.com/forum/#!topic/comp.dsp/GFAzbora6bE
const as single w=.005*(8*atn(1)) 'w= radians per step (so here 200 steps = 2*Pi radians =360 degrees) dim as single u=0!,v=1!,k1=tan(w*.5),k2=2*k1/(1 + k1*k1) for j as ulong =0 to 199 var tmp = u - k1*v v = v + k2*tmp u= tmp - k1*v var i=j mod 800 pset (i,225+200*v),rgb(255,0,255) pset (i,225+200*u),rgb(0,255,255) pset (400+100*v,225+100*u),rgb(255,255,255) next