Page 75 - 49A Field Guide to Genetic Programming
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Chapter 7
Linear and Graph
Genetic Programming
Until now we have been talking about the evolution of programs expressed
as one or more trees which are evaluated by a suitable interpreter. This is
the original and most widespread type of GP, but there are other types of
GP where programs are represented in different ways. This chapter will look
at linear programs and graph-like (parallel) programs.
7.1 Linear Genetic Programming
In linear GP programs are linear sequences of instructions, such as the one
in Figure 7.1. The number of instructions can be fixed, meaning that every
program in the population has the same length, or variable, meaning that
different individuals can be of different sizes. In the following sections we
discuss reasons for using linear GP (Section 7.1.1). We then provide more
details on the different flavours of linear GP (Section 7.1.2). Finally, we
describe briefly the main genetic operations for linear GP (Section 7.1.3).
7.1.1 Motivations
There are two different reasons for trying linear GP. Firstly, almost all
computer architectures represent computer programs in a linear fashion with
....
Instruction 1 Instruction 2 Instruction N
Figure 7.1: Typical linear GP representation for programs.
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