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julia(6x) XScreenSaver manual julia(6x)


julia - draws spinning, animating julia-set fractals


julia [--display host:display.screen] [--foreground color] [--background color] [--window] [--root] [--window-id number][--mono] [--install] [--visual visual] [--ncolors integer] [--delay microseconds] [--cycles integer] [--count integer]



The julia program draws spinning, animating julia-set fractals.

It uses ifs {w0 = sqrt(x-c), w1 = -sqrt(x-c)} with random iteration to plot the julia set, and sinusoidially varied parameters for the set, and plots parameters with a circle.

One thing to note is that count is the depth of the search tree, so the number of points computed is (2^count)-1. I use 8 or 9 on a dx266 and it looks okay. The sinusoidal variation of the parameter might not be as interesting as it could, but it still gives an idea of the effect of the parameter.

Dragging the mouse in the window uses the mouse's position as the control point for the generation of ths set.


julia accepts the following options:

Draw on a newly-created window. This is the default.
Draw on the root window.
--window-id number
Draw on the specified window.
If on a color display, pretend we're on a monochrome display.
Install a private colormap for the window.
Specify which visual to use. Legal values are the name of a visual class, or the id number (decimal or hex) of a specific visual.
How many colors should be used (if possible). Default 200. The colors used cycle through the hue, making N stops around the color wheel.

Display the current frame rate and CPU load.


to get the default host and display number.
to get the name of a resource file that overrides the global resources stored in the RESOURCE_MANAGER property.
The window ID to use with --root.


X(1), xscreensaver(1), xlock(1)


Copyright © 1995 by Sean McCullough.

Permission to use, copy, modify, and distribute this software and its documentation for any purpose and without fee is hereby granted, provided that the above copyright notice appear in all copies and that both that copyright notice and this permission notice appear in supporting documentation.


Sean McCullough <>, 1995.

Ability to run standalone or with xscreensaver added by Jamie Zawinski <>, 10-May-97.

6.09 (07-Jun-2024) X Version 11