On Wed, 17 Nov 2004, Hiram Berry wrote:
I understand that the periodicity=0 option is supposed to not plot orbits that go off the screen or bailout.
No. Going off the screen has nothing to do with it. And you CAN'T plot points that go off the screen (consider the virtual screen to be real, because it does take space in your video RAM). If you don't want to plot points that exceed the bailout value, then set outside to "numb". The periodicity checking is an approximation of the inner set. If the orbit cycles or becomes periodic, then enabling periodicity checking (and I disable it by default) will detect this and count the pixel as inside before the iterations maximum has been reached. It is more effective in saving time at high iteration counts. Methods { ; A look at the internals of tesseral, border tracing, ; and diffusion at the inversion of where x=log(2)/2. ; (A slight revision of my previous posting, this ; zooms in slightly to make border-tracing work). reset=2003 type=mandel passes=b center-mag=-0.533722/6.66134e-016/1.00621/1.5686/-90/3.885780586188047\ 89e-016 params=0/0 float=y maxiter=255 fillcolor=2 inside=255 invert=0.47/-0.333333333333333/0 periodicity=-2 colors=0zzzzz00zz0zz0Wz00zV0zz0<3>0z00zV0zz<3>00zV0zz0z<3>z00<3>ze0zo0\ zz0Wz00z0<3>0ze0zo0zz<3>00zV0zz0z<3>z00<3>ze0zo0zz0<3>Lz0Bz00z00zV0zz<\ 3>0Lz0Bz00z<3>z0zz0Wz00<3>ze0zo0zz0<3>0z0<3>0ze0zo0zz<3>0Wz0Oz0Gz08z00\ z<3>z0zz0Wz00<3>zz0Wz00z0<3>0zz<7>0Rz0Nz0Iz<3>00z<3>z0z<3>z0Lz0Bz00zV0\ zz0<3>az0Wz0Qz0<3>0z00zV0zz<3>0Lz0Bz00z<3>e0zo0zz0z<3>z00<3>ze0zo0zz0<\ 3>Lz0Bz00z00zV0zz<3>0az0Wz0Qz<3>00zV0zz0z<3>z00zV0zz0<5>Wz0Rz0Lz0<3>0z\ 0<5>0zV0z_0ze<3>0zz<3>00zV0zz0z<3>z00<3>ze0zo0zz0Wz00z0<3>0zP0zV0z`<3>\ 0zz<3>000 } The above fractal was meant to be rendered with different methods, but I'll explain what I see in this. The yellow and white lines both contrast with blue. You'll see where x=-.16 and y=.6 that blue and yellow dominate. With passes=g, this area will be filled with yellow. With passes=d, you'll get the same thing. Only tesseral identifies this as disputed territory. What about border-tracing? It colours the disputed territory, and ONLY the disputed territory. _______ Shaw's Principle: Build a system that even a fool can use, and only a fool will want to use it.