XMS

Section: User Commands (1)
Updated: 24 Nov 1991
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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.

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 X11R4 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 under X11R4, 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. These options currently work only if xms has been compiled with the X11R4 library.
-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 work only with the X11R4 library.

FILES

/usr/local/etc/mslaveslist of computation server hosts

$HOME/.mslaves per-user override of the above

ENVIRONMENT

DISPLAY the default host and display.

COPYRIGHT

This document was created by man2html, using the manual pages.
Time: 17:14:17 GMT, January 16, 2023

XMS