rpart_nodes {TSDT}

rpart_nodes

Description

Extract node information from an rpart.object.

Usage

rpart_nodes(tree)

Arguments

tree

An rpart.object returned from call to rpart().

Details

Information about nodes and splits returned in an rpart.object is contained in strings printed to the console. This function parses those strings and populates a data.frame.

Value

A data.frame containing the nodes of a parsed tree.

See Also

rpart, rpart.object

Examples

requireNamespace( "rpart", quietly = TRUE )
## Generate example data containing response, treatment, and covariates
N <- 50
continuous_response = runif( min = 0, max = 20, n = N )
binary_response <- sample( c('A','B'), size = N, prob = c(0.5,0.5),
                           replace = TRUE )
trt <- sample( c('Control','Experimental'), size = N, prob = c(0.4,0.6),
               replace = TRUE )
X1 <- runif( N, min = 0, max = 1 )
X2 <- runif( N, min = 0, max = 1 )
X3 <- sample( c(0,1), size = N, prob = c(0.2,0.8), replace = TRUE )
X4 <- sample( c('A','B','C'), size = N, prob = c(0.6,0.3,0.1), replace = TRUE )

## Fit an rpart model with continuous response (i.e. regression)
fit1 <- rpart::rpart( continuous_response ~ trt + X1 + X2 + X3 + X4 )
fit1

## Parse the results into a new data.frame
ex1 <- rpart_nodes( fit1 )
ex1

## Fit an rpart model with binary response (i.e. classification)
fit2 <- rpart::rpart( binary_response ~ trt + X1 + X2 + X3 + X4 )
fit2