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Next: 21.2.1 Alter the number Up: 21 Mutation. Previous: 21.1 The first mutation

21.2 Flip bits.

If ``b'' is selected at the first mutation prompt (#21.1) above, the default number of bits to be flipped (at random) may be altered. The original default is to flip one bit. Successive mutations are cumulative. The following option depends on whether the network has one homogeneous rule, or a rule mix. In this example, the neighbourhood size k=5, and the network size n=10.

In a network with one homogeneous rule the random bitflips apply to one rule only. The maximum number of bits that may be flipped equals the size of the rule table. The following prompt is presented:

bits to flip=1/32=12%: all-a number-n percentage-p (values shown are examples)

In a mixed rule (or neighbourhood) network, the total number of bits specifying the rule scheme is the sum of the bits in n rule tables. This number is shown in the prompt below for a k=5, n=10 network, and is the basis for percentage setting. Mutations are made by picking a random bit of a random cell's rule table for each bit flip.

bits to flip=1/320=0.312%: all-a number-n percentage-p (values shown are examples)

If ``a'' is entered, a new rule scheme is assigned at each mutation.