Can't read the labels on a hierarchical clustering plot

Question

I am in 2 weeks into programming into R, and I am doing hierarchical clustering (using agnes) on a set of 150 documents. When I do the clustering, the plot looks really bad as all of the labels overlap, it basically looks like a mess. What is the best way to

• create a larger plot that I can zoom in if need be to read labels
• creating smaller font, that is also readable

Here's the code I'm using

 cluster<- agnes(sim_matrix,diss="TRUE",method="ward")
 dimnames(sim_matrix) = list(docnames, docnames)
 plot(cluster)

Answer 1

Save the output to a file:

pdf(file="dendrogram.pdf", height=10, width=30)
plot(cluster, which.plots=2, cex=1)
dev.off()

Change the height and width of the pdf until the labels and the dendrogram are visible. You can also adjust font size via cex argument.

If you prefer the PNG or other file formats, check ?png