1xlyap(6x)                     XScreenSaver manual                    xlyap(6x)
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NAME

6       xlyap - display an array of Lyapunov exponents graphically
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SYNOPSIS

9       xlyap [-BLps] [-W width] [-H height] [-o filename] [-a n] [-b n] [-w n]
10               [-h n] [-i xstart] [-M n] [-R p] [-S n] [-D n] [-F string]  [-f
11               string]  [-r n] [-O n] [-C n] [-c n] [-m n] [-x xpos] [-y ypos]
12               [--fps] [--visual visual] [--window] [--root] [--window-id num‐
13               ber]
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DESCRIPTION

16       xlyap generates and graphically displays an array of Lyapunov exponents
17       for a variety of iterated periodically forced non-linear  maps  of  the
18       unit interval.
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OPTIONS

21       -random A  good  choice for use with xscreensaver: picks random parame‐
22               ters from a built-in list.
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24       -C n    Specifies the minimum color index to be used for negative expo‐
25               nents
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27       -D n    Specifies the "dwell" or number of iterations over which to av‐
28               erage in order to calculate the Lyapunov exponent.  Default  is
29               50.
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31       -H n    Specifies the height of the window. Default is 256.
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33       -L      Indicates use log(x) + log(y) rather than log(xy).
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35       -M r    Specifies  the real value to compare exponent values to for in‐
36               dexing into a color wheel. The default value is 1.0.
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38       -O n    Specifies the minimum color index to be used for positive expo‐
39               nents
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41       -R p    Specifies pseudo-random forcing with probability p of using pa‐
42               rameter value 'a'.
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44       -S n    Specifies the "settle" or number of iterations prior to the be‐
45               ginning of the calculation of the Lyapunov exponent. Default is
46               50.
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48       -a r    Specifies the real value to use as the minimum parameter  value
49               of the horizontal axis. Default is 2.0 for the logistic map.
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51       -b n    Specifies  the real value to use as the minimum parameter value
52               of the vertical axis. Default is 2.0 for the logistic map.
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54       -c n    Selects one of six different color wheels to use.  The  default
55               color wheel is a rainbow palette.
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57       -F 10101010
58               Specifies  the  "Function" forcing function to use. The example
59               above would alternate between iterating the circle and logistic
60               maps. An argument of "-F 2323" would alternate between left and
61               right logistic maps. The default is  to  only  use  the  single
62               specified map (see the description of -m).
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64       -f abbabaab
65               Specifies the forcing function to use. The default is to alter‐
66               nate between the "a" parameter and the "b" parameter.
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68       -h r    Specifies the real value to be used as the range over which the
69               vertical parameter values vary. The default is 1.0.
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71       -i r    Specifies  the  real value of the initial condition to use. De‐
72               fault is 0.65.
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74       -m n    Selects between available non-linear maps of the unit interval.
75               A value of 0 specifies the logistic map. A value of 1, the cir‐
76               cle map. A value of 2, the left-logistic. A  value  of  3,  the
77               right-logistic.  A value of 4, the double-logistic. The default
78               is 0, the logistic map.
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80       -o filename
81               Specifies the output filename to be used. If the -o  option  is
82               given,  this file will automatically be written out at the com‐
83               pletion of the drawing.  If it  is  not  specified,  a  default
84               filename of lyap.out is used and only written if the 'f' or 'F'
85               keys are pressed during a run. The format of the output file is
86               PPM  for  color  and PGM for monochrome. The parameters used to
87               calculate the picture are included as comments at the beginning
88               of the output file.
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90       -p      Switches  color  indices  for  negative and positive exponents.
91               Generally, causes negative exponents to be  displayed  in  more
92               detail  while darkening and narrowing the color range for posi‐
93               tive exponents. This can be toggled during runtime by  pressing
94               the 'p' key.
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96       -r n    Specifies the maximum rgb value to be used. Default is 65000.
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98       -s n    Specifies the length of the color wheel spin.
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100       -v      Prints out the various values to be used and exits.
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102       -w r    Specifies the real value to be used as the range over which the
103               horizontal parameter values vary. The default is 1.0.
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105       --visual visual
106               Specify which visual to use.  Legal values are the  name  of  a
107               visual  class,  or the id number (decimal or hex) of a specific
108               visual.
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110       --window
111               Draw on a newly-created window.  This is the default.
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113       --root  Draw on the root window.
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115       --window-id number
116               Draw on the specified window.
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NOTES

119       During display, pressing any mouse button allows you to select the area
120       to  be  investigated  with the mouse. The upper left hand corner of the
121       desired area is the location of the cursor when the button is  pressed.
122       The  lower right hand corner is specified by the cursor when the button
123       is released.
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125
126       Use of the keys bBeEfFkKjJmnrRsSwWxXqQ indicates:
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128          (<) Halve dwell value.
129          (>) Double dwell value.
130          ([) Halve settle value.
131          (]) Double settle value.
132          (B or b) Toggle button display on/off
133          (E or e) Recalculate the indices into the color wheel using  a  dif‐
134       ferent method
135          (F or f) Save current screen to output file (not yet implemented)
136          (H or h or ?) Display brief help message
137          (i)  Decrement  the  interval  between stripes for the striped color
138       map.
139          (I) Increment the interval between stripes  for  the  striped  color
140       map.
141          (K) Decrease value exponents are compared against by 0.05.
142          (J) Increase value exponents are compared against by 0.05.
143          (M) Decrease value exponents are compared against by 0.005.
144          (N) Increase value exponents are compared against by 0.005.
145          (m) Increment the map index, changing the map to be iterated.
146          (P or p) Toggle positive/negative exponent display.
147          (r) Redraw the window using previously calculated exponents.
148          (R)  Redraw  the window using the newly set dwell and/or settle val‐
149       ues.
150          (S) Spin the color wheel
151          (s) Halve the length of the spin and spin the color wheel
152          (u) Go up to the window just prior to the most recent zoom.
153          (U) Go all the way up to the original window.
154          (V or v) Display values of various parameters currently in use
155          (W or w) Use next color map.
156          (X or x) Clear window
157          (Q or q) quit
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ENVIRONMENT

160       DISPLAY to get the default host and display number.
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162       XENVIRONMENT
163               to get the name of a resource file that  overrides  the  global
164               resources stored in the RESOURCE_MANAGER property.
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166       XSCREENSAVER_WINDOW
167               The window ID to use with --root.
168

SEE ALSO

170       X(1), xscreensaver(1)
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AUTHOR

173       Ronald Joe Record
174       The Santa Cruz Operation
175       P.O. Box 1900
176       Santa Cruz, CA 95061
177       rr@sco.com
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ACKNOWLEDGEMENTS

180       The algorithm was taken from the September 1991 Scientific American ar‐
181       ticle by A. K. Dewdney who gives credit to  Mario  Markus  of  the  Max
182       Planck  Institute  for  its  creation. Additional information and ideas
183       were gleaned from the  discussion  on  alt.fractals  involving  Stephen
184       Hall,  Ed  Kubaitis,  Dave  Platt and Baback Moghaddam. Assistance with
185       colormaps and spinning color wheels and X was gleaned from Hiram  Claw‐
186       son.  Rubber  banding code was adapted from an existing Mandelbrot pro‐
187       gram written by Stacey Campbell.
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189       Viciously hacked for xscreensaver by Jamie Zawinski, 20-Nov-97.
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193X Version 11               6.08-1.fc39 (17-Oct-2023)                 xlyap(6x)
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