#: 5734 S10/Tandy CoCo
    31-Jul-90  20:21:27
Sb: #5731-#Fractal.ar
Fm: Bruce MacKenzie 71725,376
To: James Jones 76257,562 (X)

James,
     I don't see how you could write the program using integer math.  In the
original rsdos/asm version I actually wrote my own 2 byte mantissa floating
point routines to speed things up.  But I was younger then and impatient.  This
time through I decided to push the resolution to the limit.
     It would be posible to use symmetry to speed things up in certain cases. 
The Mandelbrot set has a plane of symmetry about y=0 and Julia sets have
inversion symmetry about the origin.  The problem is that in order use this the
pixle grid must be symmetrically disposed wrt the symmetry element--which in
general it isn't.  You could fudge things to get the grid in line but if the
symmetry element is off screen you can't use it anyway.  I considered all this
and decided it introduced too many if--thens in an otherwise clean algorithm.
     In a couple of places I've seen reference to faster algorithms for
generating the sets.  I beleive this involves successive distortions of a line
converging on the outline of the set.  But I've never heard described exactly
how this is done.  If anybody knows anything about this I'd be interested in
hearing about it.

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