Many options are provided for the presentation of attractor basins and space-time patterns. Again, many of these settings can be changed ``on the fly``, including the scale and colour of space-time patterns. Cells in space-time patterns are coloured according to their value (0,1) or alternatively according to their neighbourhood at the previous time step (the entry in the look-up table that determined the cell's value). A key press will toggle between the two. Alternatively, the colour presentation can be set to highlight cells that have not changed in the previous x generations, where x can be set to any value. The development of such frozen clusters, which may link up into percolating walls, is associated with canalyzing ``genes``, and underlies Kauffman's ``random Boolean network '' model of gene regulatory networks (Kauffman 1993).
A 1d space-time pattern is presented in successive vertical sweeps, or may be scrolled. 2d networks (including the ``game of life'' or any mutation thereof) can be displayed as a space-time pattern in a 3d isometric projection (as if looking up at a glass lift shaft). The projection can be toggled between 3d, 2d and 1d (which shows a series of slices).
For attractor basins, options allow the selection of the basin of attraction field, a single basin (from a selected seed), or a sub-tree (also from a seed). A random seed is likely to be a garden of Eden state. For sub-trees, an option is therefore offered to run the network forward a given number of steps to a new seed before running backward. This guarantees a sub-tree with at least that number of levels.
Options (and defaults) are provided for the layout of attractor basins, their size, position, spacing, and type of node display (as a spot, in decimal, hex or a (1d or 2d) bit pattern). Regular 1d and 2d CA produce attractor basins where sub-trees and basins are equivalent by rotational symmetry. This allows ``compression'' of basins (by default) into non-equivalent prototypes, though compression can be suppressed. Attractor basins can be generated for a given system size, or automatically for a range of sizes. As attractor basins are generating, the reverse space-time pattern can be displayed either by sweeps or scrolled. The 1s in each state are shown in black, 1s in predecessors (if any) in red.
An attractor basin run can be set to pause to see data on each transient tree, each basin, or each field. Normally the run will pause before the next ``mutant'' attractor basin, but this pause may be turned off to create a continuous demo of new attractor basins. A ``screensave'' demo option shows new basins continually growing in random position. At any time, a space-time pattern or attractor basin run can be interrupted to pause, save or print the screen image, or backtrack through options.
In the DOS version the graphics will start up in VGA (640x480) unless the program parameter ``-h'' is set (for high resolution SVGA (1024x768). The resolution can subsequently be toggled between VGA and SVGA (SVGA requires an appropriate monitor, graphics card and driver, and the mouse is not visible though mouse functions work). In the XWindows version the DDLab window starts up at 1024x768 but can be resized, moved and iconised in the usual way.
The background color is by default white, but can be reset to black either from within the program or by setting the program parameter ``-b``, i.e. for a black background start DDLab by entering ``ddlab -b``.