extract_dummy_variables: Transform Categorical Covariate into Dummy Variables

In TimeDepFrail: Time Dependent Shared Frailty Cox Model

Transform Categorical Covariate into Dummy Variables

Description

This function produces for a categorical variable of the dataset (covariate) the associated dummy variables: for n levels of the covariate, (n-1) dummy binary variables are generated. The chosen reference value is the first one of the list of extracted levels and cannot be changed (the first one in alphabetical order). Therefore, if an individual has null value for all dummy variables, then his/her belonging level is the reference one.

Each dummy variable has a name, corresponding to the name of the covariate + name of the level.

Usage

extract_dummy_variables(covariate, covariate_name)

Arguments

covariate	Categorical dataset covariate, with at least 2 levels.
covariate_name	Name of the covariate, for assigning each dummy variable a proper name.

Details

The S3 class object 'DummyData' contains the variables related to the transformation of a single categorical covariate present in the dataset into (n-1) binary covariates, stored in a matrix. To be precise:

• DummyMatrix: binary matrix of dimension (n_individuals, n-1), where each column corresponds to one level of the original categorical covariate.

• DummyVariablesName: categorical vector of length (n-1), reporting the names of the dummy variables and, therefore, the new name of each regressor.

• DummyVariablesNumber: number of dummy variables (n-1).

Value

S3 object of class 'DummyData', composed of three elements. See details.

TimeDepFrail documentation built on April 11, 2025, 5:41 p.m.