aUCBLogo Demos and Tests / julia

to julia
;   c=-1+0i
;   c=0.360284+0.100376i
   c=0.315209+0.03758i
   cs hT
   t=timefine
   juliaset c
   (pr timefine-t "seconds)
end

to juliaset c
   local [c1 c2 extent half quarter m n x0 y0 x y xs j z]
   c1 = real(c) ; -1.0      # default is -1.0 + 0.0i
   c2 = imag(c) ;  0.0
   extent = 600
   half = 600 / 2
   quarter = extent / 4
   maxiter=100
   color=array maxiter
   repeat maxiter
   [   color.repcount=hsb 240*repcount/maxiter 1 1
   ]
   repeat extent
   [   m=repcount
      x0=-2+m/quarter
      repeat half
      [   n=repcount
         y0=2-n/quarter
         z=x0+y0*1i
         j=mandelIterate z c maxiter
         setPixel se m-half n-half  color.j
         setPixel (se half-m half-n) color.j
      ]
      if (mod m 16)==0 [updateGraph]
   ]
end

to mandelIterate_old z c maxiter
   repeat maxiter   ; compute orbit
   [   z*=z
      z+=c
      if z > 4 [output repcount]
   ]
   output maxiter
end