ggdendro (version 0.2.0)

dendro_data.tree: Extract data from regression tree object for plotting using ggplot.

Description

Extracts data to plot line segments and labels from a tree::tree() object. This data can then be manipulated or plotted, e.g. using ggplot2::ggplot().

Usage

# S3 method for tree
dendro_data(model, type = c("proportional", "uniform"), ...)

Value

A list of three data frames:

segments

a data frame containing the line segment data

labels

a data frame containing the label text data

leaf_labels

a data frame containing the leaf label text data

Arguments

model

object of class "tree", e.g. the output of tree()

type

Either proportional or uniform. If this partially matches "uniform", the branches are of uniform length. Otherwise they are proportional to the decrease in impurity.

...

ignored

Author

Andrie de Vries, using code modified from original by Brian Ripley

See Also

ggdendrogram()

Other dendro_data methods: dendro_data(), dendro_data.rpart(), dendrogram_data(), rpart_labels()

Other tree functions: get_data_tree_leaf_labels(), tree_labels(), tree_segments()

Examples

### Demonstrate tree

if (require(tree)) {
  require(ggplot2)
  require(MASS)
  data(cpus, package = "MASS")
  cpus.ltr <- tree(log10(perf) ~ syct + mmin + mmax + cach + chmin + chmax, 
                   data = cpus)
  tree_data <- dendro_data(cpus.ltr)
  ggplot(segment(tree_data)) +
    geom_segment(aes(x = x, y = y, xend = xend, yend = yend, linewidth = n),
      colour = "lightblue"
    ) +
    scale_size("n") +
    geom_text(
      data = label(tree_data),
      aes(x = x, y = y, label = label), vjust = -0.5, size = 4
    ) +
    geom_text(
      data = leaf_label(tree_data),
      aes(x = x, y = y, label = label), vjust = 0.5, size = 3
    ) +
    theme_dendro()
}