xms
NAME
xms - X MandelSpawn, a network Mandelbrot program for X11
SYNOPSIS
xms [ -iterations n ] [ -colours n ] [ -wrap ] [ -spectrum
colour-colour- ... -colour ] [ -greyscale ] [ -center ] [
-nocenter ] [ -cursor cursor ] [ -x coord ] [ -y coord ] [
-range r ] [ -julia ]
DESCRIPTION
Xms is a program for interactive display of the Mandelbrot
and Julia sets under the X window system. You can select an
area of interest using the mouse and zoom in on it either in
the same window or by popping up a new window.
Xms relies on "computation server" processes (see
mslaved(8)) running on one or more machines to do the actual
computations.
STARTING XMS
Make sure you have started one or more computation servers
and listed them in your .mslaves file before you start xms.
If you have no .mslaves file, xms will try to start a single
computation server on the local host; this will only succeed
if the mslaved program is in the path.
If xms does not get a response from any computation server,
its windows will simply stay blank until some server
responds.
INTERACTING WITH XMS
When xms starts up, it first creates an initial window
showing the entire Mandelbrot set. The window may be moved
or stretched using the window manager. You can select an
area to zoom into using the left mouse button, and then zoom
in by pressing the middle button or the z key. Normally a
new window is created for the zoomed image, but if you want
to reuse the original window you can do that by keeping the
shift key depressed while zooming.
If xms has been compiled with the Xaw library, the right
mouse button pops up a menu with several self-explanatory
options. Without Xaw, pressing the right mouse button (or
the c key) closes the window pointed to, and shift-right
button (or pressing q) causes the program to exit,
destroying all its windows.
Pressing the j key (j as in Julia) pops up a new window
showing the Julia set corresponding to the point at the
center of the selected area. The o key zooms out in such a
way that what is currently visible in the window will be be
positioned in the selected area after the zoom. These keys
may also be used together with the shift key. It is also
possible to zoom out by dragging the rubberband box outside
the window and then zoom using z or the middle mouse button.
Pressing w causes the window coordinates to be printed on
the standard output, and s prints various statistics about
computation server performance.
COMMAND LINE OPTIONS
In addition to the standard Xt options, xms provides the
following options:
-iterations n
Specifies the maximum number of iterations. The
default is 250.
-colours n
Specifies the number of colours or shades of grey to
use. Because white and black are needed for the popup
menu, you need to specify a value that is at least 2
less than the number of colours supported by the
hardware. The default value for -colours is the value
of -iterations. The default of 250 iterations leaves 6
colours for other applications on an 8-plane display,
thus avoiding the "technicolor effect" in most cases.
If you have less than 250 colours available (Motif
users often do), you will have to specify either the
-iterations or -colours option. If -colours is less
than -iterations, the same colour is reused for several
consecutive iteration counts or, if the -wrap option
was given, the same sequence of colours will be
repeated as many times as necessary. The areas
corresponding to the maximum iteration count, i.e. the
inside of the Mandelbrot set, will always use the last
colour of those specified with the -spectrum option.
Has no effect with a single-plane display.
-wrap
See above.
-spectrum colour-colour- ... -colour
Uses the specified colours or shades of grey (can only
be used with a colour or greyscale display). The first
one is used for the area outside the circle with radius
2 around the origin, the last one is used for the
Mandelbrot set itself. For intervening iteration
counts the colour is found by interpolating linearly in
RGB space between pairs of the colours given in the
argument.
-greyscale
This is a synonym for "-spectrum white-black".
-center
Causes the center of the rubberband box to remain fixed
while a corner follows the cursor when selecting an
area to zoom into. This is the default.
-nocenter
Causes one corner of the rubberband box to remain fixed
while the opposite corner follows the cursor when
selecting an area to zoom into.
-cursor cursor
Specifies the type of cursor.
-x, -y, -range
Specify the center coordinates and horizontal width,
respectively, of the part of the Mandelbrot or Julia
set shown in the initial window.
-julia
Causes the initial window to show a Julia set instead
of a Mandelbrot set. The "-cx" and "-cy" options may
be used to choose the c parameter for the Julia set.
BUGS
By zooming out from the initial picture it is possible to
view areas (starting at a distance of about 10 from the
origin) where the fixed-point arithmetic used by some
servers overflows. This bug remains unfixed because some
users think the fractal interference patterns caused by the
overflow look at least as interesting as the Mandelbrot set
itself.
The -x, -y, -range, -cx, and -cy options are not supported
under pre-X11R4 versions of Xt.
FILES
/usr/local/etc/mslaves list of computation server hosts
$HOME/.mslaves per-user override of the above
SEE ALSO
X(1), X(8C), mslaved(8), mslavedc(8), enslave(1)
ENVIRONMENT
DISPLAY the default host and display.
COPYRIGHT
Copyright (C) 1990, 1991 Andreas Gustafsson
(gson@niksula.hut.fi)