Page 87 - 49A Field Guide to Genetic Programming

8.2 Pure EDA GP 73

+ 0.1
* 0.2
-
0.1
/ 0.2
x 0.3
R 0.1

+ 0.2 + 0.1
* 0.3 - 0.1
*
-
0.1
0.1
/ 0.1 / 0.4
x 0.2 x 0.3
R 0.1 R 0.0

+ 0.1 + 0.0 + 0.1 + 0.3
*
-
* 0.2 * 0.0 * 0.1 - 0.1
-
-
0.2
0.0
0.1
0.3
/ 0.0 / 0.1 / 0.1 / 0.0
x 0.4 x 0.1 x 0.2 x 0.3
R 0.2 R 0.5 R 0.3 R 0.3

Figure 8.1: Example of probability tree used for the generation of programs
in PIPE. New program trees are created starting from the root node at the
top and moving through the hierarchy. Each node in an offspring tree is
selected from the left hand side of the corresponding table with probability
given by the right hand side. Each branch of the tree continues to expand
until either the tree of probability tables is exhausted or a leaf (e.g., R) is
selected.