Notes on IFS file format                                April 24, 2006
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IFS files use the filename extension ".ifs".  They're  text files that
provide Fractint-compatible fractal definitions.

The following sample IFS file contains three entries that define three
corresponding iterated function systems:

Heighway {; Heighway Dragon
; Edgar, "Measure, Topology, and Fractal Geometry"
; Page 19
   0.5 -0.5  0.5  0.5  0  0  0.5
  -0.5 -0.5  0.5 -0.5  1  0  0.5
}

Fern {; Barnsley's Black Spleenwort fern
   0     0     0     0.16  0  0     .01
   0.85  0.04 -0.04  0.85  0  1.6   .85
   0.2  -0.26  0.23  0.22  0  1.6   .07
  -0.15  0.28  0.26  0.24  0  0.44  .07
}

Levy {; The Levy Dragon
   0.5, -0.5,  0.5,  0.5,  0.0,  0.0
   0.5,  0.5, -0.5,  0.5,  0.5,  0.5
}

For each entry, the first line contains the corresponding fractal name
followed by a left curly brace.

Anything after a  semi-colon is treated as an IFS comment,  and is ig-
nored for computation purposes. However, some programs can display IFS
comments. Note: Programs may impose a limit on the number of comments,
the number of comment lines, and/or the length of individual comments.

The lines  containing  numbers are data lines.  Each data line defines
one affine  transformation.  There should be  six or seven  numbers on
each  data  line. The first four numbers specify entries in the trans-
formation matrix. The next  two  numbers specify entries in the trans-
lation vector. If there's a seventh number on the line, it specifies a
probability value.

The numbers in each data line should be separated by  spaces, tabs, or
commas.

A right curly brace [on its own line] indicates the end of the current
IFS entry.

Note:  Programs may impose a  limit on the total number of IFS entries
and/or the total number of transformations per entry.