2.10 Circle
(type=circle)
This fractal types is from A. K. Dewdney's "Computer Recreations" column
in "Scientific American". It is attributed to John Connett of the
University of Minnesota.
(Don't tell anyone, but this fractal type is not really a fractal!)
Fascinating Moire patterns can be formed by calculating x^2 + y^2 for
each pixel in a piece of the complex plane. After multiplication by a
magnification factor (the parameter), the number is truncated to an
integer and mapped to a color via color = value modulo (number of
colors). That is, the integer is divided by the number of colors, and
the remainder is the color index value used. The resulting image is not
a fractal because all detail is lost after zooming in too far. Try it
with different resolution video modes - the results may surprise you!
If inside=startrail is used, it will automatically be set to inside=norm
by Fractint. This is because type circle and inside=startrail locks up
Fractint.