rdecision (version 1.1.2)

GammaModVar: A model variable whose uncertainty follows a Gamma distribution

Description

An R6 class for a model variable with Gamma uncertainty.

Author

Andrew J. Sims

Super class

rdecision::ModVar -> GammaModVar

Methods

Public methods

• GammaModVar$new()

• GammaModVar$is_probabilistic()

• GammaModVar$clone()

Inherited methods

• rdecision::ModVar$SD()
• rdecision::ModVar$description()
• rdecision::ModVar$distribution()
• rdecision::ModVar$get()
• rdecision::ModVar$is_expression()
• rdecision::ModVar$mean()
• rdecision::ModVar$mode()
• rdecision::ModVar$quantile()
• rdecision::ModVar$r()
• rdecision::ModVar$set()
• rdecision::ModVar$units()

---

Method new()

Create an object of class GammaModVar.

Usage

GammaModVar$new(description, units, shape, scale)

Arguments

description

A character string describing the variable.

units

Units of the variable, as character string.

shape

shape parameter of the Gamma distribution.

scale

scale parameter of the Gamma distribution.

Returns

An object of class GammaModVar.

---

Method is_probabilistic()

Tests whether the model variable is probabilistic, i.e. a random variable that follows a distribution, or an expression involving random variables, some of which follow distributions.

Usage

GammaModVar$is_probabilistic()

Returns

TRUE if probabilistic

---

Method clone()

The objects of this class are cloneable with this method.

Usage

GammaModVar$clone(deep = FALSE)

Arguments

deep

Whether to make a deep clone.

Details

A model variable for which the uncertainty in the point estimate can be modelled with a Gamma distribution. The hyperparameters of the distribution are the shape (k) and the scale (theta). Note that although Briggs et al (2006) use the shape, scale formulation, they use alpha, beta as parameter names. Inherits from class ModVar.

References

Briggs A, Claxton K, Sculpher M. Decision modelling for health economic evaluation. Oxford, UK: Oxford University Press; 2006.