Knowledge-Based Systems

220 Chapter 8 GenetiC alGorithms

Depending on the nature of the problem, one can adopt other ways of

encoding individuals, such as numbers and alphabets.

8.5.1 Mutation

Mutating a bit involves flipping it, changing a gene with another one with

the help of a small mutation probability P

mutation

. A number between 0 and

1 is chosen at random. If the random number is smaller than P

mutation

, the

outcome of flipping is true; otherwise, the outcome is false. If, at any bit, the

outcome is true, the bit is altered; otherwise, the bit is kept unchanged. For

binary encoding, a mutation means to flip one or more randomly chosen

bits from 1 to 0 or