#### NAME

henwarp - warps a square into the phase space of the Henon
system

#### SYNOPSIS

**henwarp** **-help**
or
**henwarp**
**[-width** *integer***]** **[-height** *integer***]** **[-swap]** **[-len**
*integer***]** **[-count** *integer***]** **[-A** *double***]** **[-B** *double***]**
**[-ulx** *double***]** **[-uly** *double***]** **[-lly** *double***]** **[-inv]**
**[-mag** *integer***]** **[-term** *string***]**

#### DESCRIPTION

A square (initially centered about the origin) is trans-
formed by the Henon system, which is described by the
equation x(t+1) = A - x(t)^2 + B * x(t - 1), a fixed num-
ber of times according to the specified parameters.

#### OPTIONS

**-width** *integer*
Width of the plot in pixels.
**-height** *integer*
Height of the plot in pixels.
**-swap** Swap the x and y axis.
**-len** *integer*
Length of edge of square.
**-count** *integer*
Number of transformations.
**-A** *double*
Value of the A parameter.
**-B** *double*
Value of the B parameter.
**-ulx** *double*
Upper-left corner x-coordinate.
**-uly** *double*
Upper-left corner y-coordinate.
**-lly** *double*
Lower-left corner y-coordinate.
**-inv** Invert all colors?
**-mag** *integer*
Magnification factor.
**-term** *string*
How to plot points.

#### MISCELLANY

You may wish to try this with a small length for the size
of square and watch how the resulting plot changes as you
slowly increase the value passed to the -count option
starting at zero. The square will slowly spread out and
converge to the attractor of the system.
The method for choosing the viewable region may seem
counter-intuitive at first, but it has some nice proper-
ties. In particular, selecting the exact (x, y) coordi-
nates for the upper-left corner and only selecting the
lower right y coordinate forces both the x and y scales to
be identical since all scales are uniquely determined by
these values along with the plot width and height. If you
then change the width or height of the plot, the relative
scales will still match up. The options for making a box
work similarly.

#### BUGS

The length of the square is in pixels and works best if it
is an odd value. With even numbered values it can produce
a gap in the plot for small values supplied with the
-count option.
No sanity checks are performed to make sure that any of
the options make sense.

#### AUTHOR

Copyright (c) 1997, Gary William Flake.
Permission granted for any use according to the standard
GNU ``copyleft'' agreement provided that the author's com-
ments are neither modified nor removed. No warranty is
given or implied.