rgp (version 0.4-1)

exprShapesOfDepth: Upper bounds for expression tree search space sizes

Description

These functions return the number of structurally different expressions or expression shapes of a given depth or size that can be build from a fixed function- and input-variable set. Here, "expression shape" means the shape of an expression tree, not taking any node labels into account. exprShapesOfDepth returns the number of structurally different expression shapes of a depth exactly equal to n. exprShapesOfMaxDepth returns the number of structurally different expression shapes of a depth less or equal to n. exprsOfDepth returns the number of structurally different expressions of a depth exactly equal to n. Note that constants are handled by conceptually substiting them with a fresh input variable. exprShapesOfMaxDepth returns the number of structurally different expressions of a depth less or equal to n. Note that constants are handled by conceptually substiting them with a fresh input variable. exprShapesOfSize, exprShapesOfMaxSize, exprsOfSize, exprsOfMaxSize are equivalents that regard expression tree size (number of nodes) instead of expression tree depth.

Usage

exprShapesOfDepth(funcset, n)
exprShapesOfMaxDepth(funcset, n)
exprsOfDepth(funcset, inset, n)
exprsOfMaxDepth(funcset, inset, n)
exprShapesOfSize(funcset, n)
exprShapesOfMaxSize(funcset, n)
exprsOfSize(funcset, inset, n)
exprsOfMaxSize(funcset, inset, n)

Arguments

funcset

The function set.

inset

The set of input variables.

n

The fixed size or depth.