julia man page

julia — draws spinning, animating julia-set fractals

TL;DR

julia

julia {{program.jl}}

julia {{program.jl}} {{arguments}}

julia -e '{{julia_code}}'

julia -e '{{for x in ARGS; println(x); end}}' {{arguments}}

julia -p {{N}}

Synopsis

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

[-fps]

Description

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.

Options

julia accepts the following options:

-window

Draw on a newly-created window.  This is the default.

-root

Draw on the root window.

-mono

If on a color display, pretend we're on a monochrome display.

-install

Install a private colormap for the window.

-visual visual

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.

-ncolors integer

How many colors should be used (if possible).  Default 200. The colors used cycle through the hue, making N stops around the color wheel.

-cycles integer
-count integer
-fps

Display the current frame rate and CPU load.

Environment

DISPLAY

to get the default host and display number.

XENVIRONMENT

to get the name of a resource file that overrides the global resources stored in the RESOURCE_MANAGER property.

See Also

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

Author

Sean McCullough <bankshot@mailhost.nmt.edu>, 1995.

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

Info

5.37-6.fc27.1 (15-Aug-2017) X Version 11 XScreenSaver manual