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.TH XScreenSaver 1 "08 Feb 2000" "X Version 11"
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critical - Draw a system showing self-organizing criticality
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[\-display \fIhost:display.screen\fP] [\-foreground \fIcolor\fP] [\-background \fIcolor\fP] [\-window] [\-root] [\-mono] [\-install] [\-visual \fIvisual\fP] [\-delay \fIseconds\fP] [\-random \fIboolean\fP] [\-ncolors \fIint\fP] [\-offset \fIint\fP]
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The \fIcritical\fP program displays a self-organizing critical system
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that gradually emerges from chaos.
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\fIcritical\fP performs a simulation on a two-dimensional array of
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integers. The array is initialized to random values. On each
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iteration, it draws a line to the array position with the greatest
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value. It then replaces that location and the eight neighboring
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locations with randomly-selected values.
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The lines are initially random, but over time a chaotic
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self-organizing system evolves: areas of the screen which happen to
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have lower values are less likely to be updated to new values, and so
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the line tends to avoid those areas. Eventually, the histogram of
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changes approaches the power-law curve typical of such systems.
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The simplest documented self-organizing system is the one-dimensional
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equivalent of \fIcritical\fP.
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I heard about this algorithm second-hand: apparently there was an
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article in \fIScientific American\fP describing it sometime in 1997.
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accepts the following options:
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Draw on a newly-created window. This is the default.
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Draw on the root window.
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If on a color display, pretend we're on a monochrome display.
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Install a private colormap for the window.
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.B \-visual \fIvisual\fP
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Specify which visual to use. Legal values are the name of a visual class,
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or the id number (decimal or hex) of a specific visual.
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.B \-delay \fIusecs\fP
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Number of microseconds to wait after drawing each line.
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.B \-random \fIboolean\fP
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Whether to use randomly selected colours rather than a cycle around
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.B \-offset \fIinteger\fP
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The maximum random radius increment to use.
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.B \-ncolors \fIinteger\fP
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How many colors should be allocated in the color ramp (note that this
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value interacts with \fIoffset\fP.)
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.B \-trail \fIinteger\fP
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Length of the trail: between 5 and 100 is nice.
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Display the current frame rate and CPU load.
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to get the default host and display number.
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to get the name of a resource file that overrides the global resources
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stored in the RESOURCE_MANAGER property.
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.BR xscreensaver-command (1)
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.BR xscreensaver-demo (1)
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Copyright \(co 1998 by Martin Pool.
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Permission to use, copy, modify, distribute, and sell this software
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and its documentation for any purpose is hereby granted without fee,
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provided that the above copyright notice appear in all copies and that
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both that copyright notice and this permission notice appear in
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supporting documentation. No representations are made about the
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suitability of this software for any purpose. It is provided "as is"
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without express or implied warranty.
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Martin Pool <mbp@humbug.org.au>, 1998-2000. Based in part on the
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XScreenSaver code by Jamie Zawinski <jwz@jwz.org>.
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hacks/critical.man
