TGPInitializationMethod Enumeration

imFull

Grow a tree to the full depth specified. Selects a function as the root node and then recursively selects functions as child nodes until initialization depth limit is reached.

imGrow

Grows a tree up to the full depth specified. Selects a function as the root node and then recursively selects instructions (functions or terminals) as child nodes until initialization depth limit is reached. Since terminals can be selected as well as functions, this method tends to create trees where subtrees do not grow to the initialization depth

imHalfAndHalf

Alternates using imFull and imGrow for initializing individuals in the population

imRampedFull

Grow a tree to the full depth specified. Selects a function as the root node and then recursively selects functions as child nodes until depth limit is reached. However, the depth limit is ramped from 2 to the full initialization depth limit, i.e., first individual has a depth limit of 2, second individual has a depth limit of 3, etc up to the full initialization depth limit. The depth limits are evenly divided amongst the population, e.g., if there are 100 individuals and a full initialization depth limit of 10, approximately 11 individuals will have a depth limit of 2, 11 will have a depth limit of 3, etc.

imRampedGrow

Grows a tree up to the full depth specified. Selects a function as the root node and then recursively selects  instructions (functions or terminals) as child nodes until initialization depth limit is reached. Since terminals can be selected as well as functions, this method tends to create trees where subtrees do not grow to the initialization depth.

However, the depth limit is ramped from 2 to the full initialization depth limit, i.e., first individual has a depth limit of 2, second individual has a depth limit of 3, etc up to the full initialization depth limit. The depth limits are evenly divided amongst the population, e.g., if there are 100 individuals and a full initialization depth limit of 10, approximately 11 individuals will have a depth limit of 2, 11 will have a depth limit of 3, etc.

imRampedHalfAndHalf

Alternates using imRampedFull and imRampedGrow for initializing individuals in the population