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

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)
}

## Loading required package: cluster

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