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    Names: »chaos.1«

└─⟦b20c6495f⟧ Bits:30007238 EUUGD18: Wien-båndet, efterår 1987
    └─⟦this⟧ »EUUGD18/X/Chaos/chaos.1« 

TextFile

.TH CHAOS 1
.PD
.ad b
.SH NAME
chaos \- The Chaos Game for X11
.SH SYNOPSIS
.TP \w'\fBchaos\fR 'u
\fBchaos\fR
[\|\fB-bd\fR border\|] [\|\fB-bg\fR background\|] [\|\fB-bw\fR borderwidth\|]
[\|\fB-delay\fR msec\|] [\|\fB-display\fR displayname\|]
[\|\fB-dist\fR distance\|]
[\|\fB-geometry\fR geometry\|]
[\|\fB-mpoints\fR\|]
[\|\fB-out\fR bitmapfile\|]
[\|\fB-points\fR x1,y1\|[\|,x1,y2\|[\|,x3,y3\|[\|,...\|]\|]\|]\|]
[\|\fB-udelay\fR msec\|]
.SH HP-UX COMPATIBILITY
.TP 10
Origin:
User Contributed
.SH DESCRIPTION
.I Chaos
plays ``The Chaos Game'' in an X11 window.  The Chaos Game, as described
on television's ``Nova'' program (``The Strange New Science of Chaos'',
originally broadcast 31 January 1989), is a simple exercise demonstrating
\&``strange attractors'', one of the fundamental concepts in the science
of chaos.
.PP
To play The Chaos Game:
.TP 4n
1)
Draw three dots on a piece of paper, corresponding to the three
vertices of an equilateral triangle.
.TP
2)
Randomly select a point on the paper, call it
P\v'+.2v'\s-20\v'-.2v'\s0.
.TP
3)
Randomly select one of the three vertices.
.TP
4)
Generate P\v'+.2v'\s-2n\v'-.2v'\s0 as the point midway between
P\v'+.2v'\s-2n-1\v'-.2v'\s0 and the selected vertex.
.TP
5)
Repeat steps 3 and 4 ad infinitum, plotting the P values generated.
.PP
What will emerge from this random walk is \fInot\fR a page covered with
dots, but a beautiful structure containing triangles within triangles
within triangles.
.PP
\fIChaos\fR plays the game as described above.  It generates a
P\v'+.2v'\s-20\v'-.2v'\s0 randomly somewhere within the window, then
generates and plots successive P values ad infinitum.  The \fB-points\fR
and \fB-mpoints\fR command-line options allows the user to specify
shapes other than the default triangle.
.PP
Options:
.TP .5i
.B -bd
Specify border color; defaults to white.
.TP
.B -bg
Specify background color; defaults to black.
.TP
.B -bw
Specify border width in pixels; defaults to 2.
.TP
.B -delay
Specify a delay (in msec) to be performed between drawing each point.
Defaults to 10.
.TP
.B -display
Specify display on which to run; defaults to contents of DISPLAY
environment variable.
.TP
.B -dist
Allows you to specify the distance moved for each point.  Default value
is 0.5.  When this option is used, point P\v'+.2v'\s-2n\v'-.2v'\s0 will
be located the specified fraction of the distance between
P\v'+.2v'\s-2n-1\v'-.2v'\s0 and the selected vertex.
.TP
.B -geometry
Specify window geometry; defaults to =300x300+0+0.
.TP
.B -mpoints
Allows you to define your own shape other than the default triangle.
You use the cursor to place the vertices: clicking button 1 defines
a vertex at the current cursor position, clicking button 3 terminates
vertex-definition mode and begins \fIchaos\fR operation.
.TP
.B -out
Specify filename into which \fIchaos\fR will dump (on request) a bitmap
of its current picture.  Defaults to ``chaos.xbm''.  This feature is
explained below in the section on ``BUTTON BEHAVIOR''.
.TP
.B -points
Allows you to specify a set of starting vertices on the command line.
Point values are expressed in floating-point, where (0.0,0.0) maps to
the window's upper left and (1.0,1.0) maps to window's lower right.
Coordinates outside of the window are permissible.  This option can be
used to specify any number of points (although fewer than three tends to
be uninteresting).  This option is overridden by the \fB-mpoints\fR
option.
.TP
.B -udelay
Normally, \fIchaos\fR computes and renders its P values only when the
window is mapped.  If the \fB-udelay\fR option is used, \fIchaos\fR will
continue to crank away when the window is unmapped (for example,
iconified), using the delay value specified with this option.  The
points computed while the window is unmapped will appear when the window
is again mapped.
.SH NOTE
Specifying a delay value of 0 will cause \fIchaos\fR to draw into
its window at top speed, bogging down your server and, if
\fIchaos\fR is run remotely, your network.  The default delay value
was chosen to work well on a fast CPU with a fast X server \(em it is
probably too low for many systems.
.PP
If \fIchaos\fR and the server are running on the same CPU, running
\fIchaos\fR with a higher nice (nice(1)) value will usually produce
good results without 1) swamping the server, and 2) requiring you to
impose an unpleasantly long delay.
.PP
Resizing the \fIchaos\fR window will cause \fIchaos\fR to clear the
window and start over.  \fIChaos\fR will generate a new starting point
randomly somewhere within the resized window.
.SH "BUTTON BEHAVIOR"
Two pointer buttons are active in the \fIchaos\fR window:
.TP .5i
.B "Button 1"
Button 1 will cause the \fIchaos\fR window to be cleared.  \fIChaos\fR
will \fInot\fR generate a new starting point \(em it will use the
current point as the starting point.  (This is a nice way to generate a
\fIchaos\fR display without the droppings from the first few P values.)
.TP
.B "Button 3"
Button 2 will cause \fIchaos\fR to create a bitmap file containing its
current picture.  Unless changed with the \fB-out\fR option, the
file will be named ``chaos.xbm''.
.SH EXAMPLES
chaos -delay 0
.sp .5
chaos -points 0,0,.3,1,.7,1,1,0
.SH AUTHORSHIP
\fIChaos\fR was authored by Nathan Meyers of Hewlett-Packard
(nathanm@hp-pcd).  Thanks to Paul T. Keener of the University
of Pennsylvania (keener@upenn5.hpe.upenn.edu) for the -dist
option.