XMS(1) MandelSpawn XMS(1)
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.
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XMS(1) MandelSpawn XMS(1)
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
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XMS(1) MandelSpawn XMS(1)
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)
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