#### NAME

lorenz - plot the phase space of the Lorenz system

#### SYNOPSIS

**lorenz** **-help**
or
**lorenz** **[-width** *integer***]** **[-height** *integer***]** **[-skip** *integer***]**
**[-points** *integer***]** **[-A** *double***]** **[-B** *double***]** **[-C** *dou-*
*ble***]** **[-delta** *integer***]** **[-dt** *double***]** **[-x0** *double***]**
**[-y0** *double***]** **[-z0** *double***]** **[-data]** **[-xp** *string***]** **[-yp**
*string***]** **[-factor** *double***]** **[-inv]** **[-mag** *integer***]**
**[-term** *string***]**

#### DESCRIPTION

The phase space of the Lorenz system, which is described
by the three differential equations
dx/dt = A * (y - x),
dy/dt = B * x - y - z * x, and
dz/dt = x * y - C * z,
is plotted according to the specified parameters. Valid
arguments passed with the -xp and -yp options can be any
one of x(t), y(t), z(t), x(t-delta), y(t-delta), or z(t-
delta). Thus, the displayed plot can take the form of a
state space plot or a delayed coordinate plot.

#### OPTIONS

**-width** *integer*
Width of the plot in pixels.
**-height** *integer*
Height of the plot in pixels.
**-skip** *integer*
Number of initial points to skip.
**-points** *integer*
Number of points to plot.
**-A** *double*
Value of the A parameter.
**-B** *double*
Value of the B parameter.
**-C** *double*
Value of The C parameter.
**-delta** *integer*
Time delay term.
**-dt** *double*
Time step.
**-x0** *double*
Initial X value.
**-y0** *double*
Initial Y value.
**-z0** *double*
Initial Z value.
**-data** Don't plot, but print points.
**-xp** *string*
X-coordinate for plot.
**-yp** *string*
Y-coordinate for plot.
**-factor** *double*
Auto-scale expansion factor.
**-inv** Invert all colors?
**-mag** *integer*
Magnification factor.
**-term** *string*
How to plot points.

#### MISCELLANY

The plot region is determined by the points that are ini-
tially skipped. If this number is too small (i.e., it is
not very representative of the range of the plotted val-
ues), then you may need to increase the number specified
by the -skip option. Alternatively, you can adjust the
value given to -factor, which simply fractionally
increases the border of the plot.
The program uses a second-order Euler's method to perform
the numerical integration, which is sufficient for simple
tasks such as this.

#### BUGS

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.