Extract cluster data from a model into a list of data frames.

Description

This function provides a generic mechanism to extract relevant plotting data, typically line segments and labels, from a variety of cluster models.

Extract line segment and label data from dendrogram or hclust object. The resulting object is a list of data frames containing line segment data and label data.

Usage

dendro_data(model, ...)

## Default S3 method:
dendro_data(model, ...)

## S3 method for class 'dendrogram'
dendro_data(model, type = c("rectangle", "triangle"),
  ...)

## S3 method for class 'hclust'
dendro_data(model, type = c("rectangle", "triangle"), ...)

## S3 method for class 'twins'
dendro_data(model, type = c("rectangle", "triangle"), ...)

Arguments

Details

For dendrogram and tree models, extracts line segment data and labels.

Value

a list of data frames that contain the data appropriate to each cluster model

A list with components:

See Also

There are several implementations for specific cluster algorithms:

• dendro_data.hclust

• dendro_data.dendrogram

• dendro_data.tree

• dendro_data.rpart

To extract the data for line segments, labels or leaf labels use:

• segment: the line segment data

• label: the text for each end segment

• leaf_label: the leaf labels of a tree diagram

ggdendrogram

Other dendro_data methods: dendro_data.rpart, dendro_data.tree, dendrogram_data, rpart_labels

Other dendrogram/hclust functions: dendrogram_data

Examples

require(ggplot2)

### Demonstrate dendro_data.dendrogram

model <- hclust(dist(USArrests), "ave")
dendro <- as.dendrogram(model)

# Rectangular lines
ddata <- dendro_data(dendro, type="rectangle")
ggplot(segment(ddata)) + 
  geom_segment(aes(x=x, y=y, xend=xend, yend=yend)) + 
  coord_flip() + 
  scale_y_reverse(expand=c(0.2, 0)) + 
  theme_dendro()

# Triangular lines
ddata <- dendro_data(dendro, type="triangle")
ggplot(segment(ddata)) + 
  geom_segment(aes(x=x, y=y, xend=xend, yend=yend)) + 
  theme_dendro()

# Demonstrate dendro_data.hclust

require(ggplot2)
hc <- hclust(dist(USArrests), "ave")

# Rectangular lines
hcdata <- dendro_data(hc, type="rectangle")
ggplot(segment(hcdata)) + 
  geom_segment(aes(x=x, y=y, xend=xend, yend=yend)) + 
  coord_flip() + 
  scale_y_reverse(expand=c(0.2, 0)) + 
  theme_dendro()

# Triangular lines
hcdata <- dendro_data(hc, type="triangle")
ggplot(segment(hcdata)) + 
  geom_segment(aes(x=x, y=y, xend=xend, yend=yend)) +
  theme_dendro()


### Demonstrate the twins of agnes and diana, from package cluster

if(require(cluster)){
  model <- agnes(votes.repub, metric = "manhattan", stand = TRUE)
  dg <- as.dendrogram(model)
  ggdendrogram(dg)
}


if(require(cluster)){
  model <- diana(votes.repub, metric = "manhattan", stand = TRUE)
  dg <- as.dendrogram(model)
  ggdendrogram(dg)
}