LeafNode {rdecision}

A leaf node in a decision tree

Description

An R6 class representing a leaf (terminal) node in a decision tree.

Details

Represents a terminal state in a tree, and is associated with an incremental utility. Inherits from class Node.

Super class

rdecision::Node -> LeafNode

Methods

Public methods

• LeafNode$new()

• LeafNode$modvars()

• LeafNode$set_utility()

• LeafNode$set_interval()

• LeafNode$utility()

• LeafNode$interval()

• LeafNode$QALY()

• LeafNode$clone()

Inherited methods

• rdecision::Node$label()
• rdecision::Node$type()

Method new()

Create a new LeafNode object; synonymous with a clinical outcome.

Usage

LeafNode$new(
  label,
  utility = 1,
  interval = as.difftime(365.25, units = "days")
)

Arguments

label

Character string; a label for the state; must be defined because it is used in tabulations. The label is automatically converted to a syntactically valid (in R) name to ensure it can be used as a column name in a data frame.

utility

The incremental utility that a user associates with being in the health state for the interval. Intended for use with cost benefit analysis. Can be numeric or a type of ModVar. If the type is numeric, the allowed range is -Inf to 1; if it is of type ModVar, it is unchecked.

interval

The time interval over which the utility parameter applies, expressed as an R difftime object; default 1 year.

Returns

A new LeafNode object

Method modvars()

Find all the model variables of type ModVar that have been specified as values associated with this LeafNode. Includes operands of these ModVars, if they are expressions.

Usage

LeafNode$modvars()

Returns

A list of ModVars.

Method set_utility()

Set the incremental utility associated with the node.

Usage

LeafNode$set_utility(utility)

Arguments

utility

The incremental utility that a user associates with being in the health state for the interval. Intended for use with cost benefit analysis. Can be numeric or a type of ModVar. If the type is numeric, the allowed range is -Inf to 1, not NA; if it is of type ModVar, it is unchecked.

Returns

Updated Leaf object.

Method set_interval()

Set the time interval associated with the node.

Usage

LeafNode$set_interval(interval)

Arguments

interval

The time interval over which the utility parameter applies, expressed as an R difftime object; default 1 year, not NA.

Returns

Updated Leaf object.

Method utility()

Return the incremental utility associated with being in the state for the interval.

Usage

LeafNode$utility()

Returns

Incremental utility (numeric value).

Method interval()

Return the interval associated with being in the state.

Usage

LeafNode$interval()

Returns

Interval (as a difftime).

Method QALY()

Return the quality adjusted life years associated with being in the state.

Usage

LeafNode$QALY()

Returns

QALY.

Method clone()

The objects of this class are cloneable with this method.

Usage

LeafNode$clone(deep = FALSE)

Arguments

deep

Whether to make a deep clone.

Author(s)

Andrew J. Sims [e-mail]