# Search NKS | Online

1 - 2 of 2 for Raster

Using early raster-based computer display technology, Mandelbrot was able to produce striking pictures of what he called fractals.

In general, the list for a particular rule can be obtained with the function
ElementaryRule[num_Integer] := IntegerDigits[num, 2, 8]
Given a rule together with a list representing the state a of a cellular automaton at a particular step, the following simple function gives the state at the next step:
CAStep[rule_List, a_List] := rule 〚 8 - (RotateLeft[a] + 2 (a + 2 RotateRight[a])) 〛
A list of states corresponding to evolution for t steps can then be obtained with
CAEvolveList[rule_, init_List, t_Integer] := NestList[CAStep[rule, #]&, init, t]
Graphics of this evolution can be generated using
CAGraphics[history_List] := Graphics[ Raster[1 - Reverse[history]], AspectRatio Automatic]
And having set up the definitions above, the Mathematica input
Show[CAGraphics[CAEvolveList[ ElementaryRule[30], CenterList[103], 50]]]
will generate the image:
The description just given should be adequate for most cellular automaton simulations.