Documentation

Tree structure to be used with Symbolic Regression algorithms. This structure is a fixed point of a n-ary tree.

Supported functions

Supported operators

create a tree with a single node representing a parameter

create a tree with a single node representing a variable

Arity of the current node

Get the children of a node. Returns an empty list in case of a leaf node.

Count the number of nodes in a tree.

Count the number of Var nodes

Count the number of const nodes

Count the number of Param nodes

Count the occurrences of variable indexed as ix

Creates the symbolic partial derivative of a tree by variable dx (if p is False) or parameter dx (if p is True).

Symbolic derivative by a variable

Symbolic derivative by a parameter

Calculates the numerical derivative of a tree using forward mode provided a vector of variable values xss, a vector of parameter values theta and a function that changes a Double value to the type of the variable values.

The function gradParams calculates the numerical gradient of the tree and evaluates the tree at the same time. It assumes that each parameter has a unique occurrence in the expression. This should be significantly faster than forwardMode.

Returns the inverse of a function. This is a partial function.

Evaluates the tree given a vector of variable values, a vector of parameter values and a function that takes a Double and change to whatever type the variables have. This is useful when working with datasets of many values per variables.

Relabel the parameters incrementaly starting from 0

Change constant values to a parameter, returning the changed tree and a list of parameter values

Same as constsToParam but does not change constant values that can be converted to integer without loss of precision

Convert the parameters into constants in the tree