Graphics Reference
In-Depth Information
Figure 13-19. Left: a dendrogram; right: with text aligned
Discussion
A cluster analysis is simply a way of assigning points to groups in an n-dimensional space (four
dimensions, in this example). A hierarchical cluster analysis divides each group into two smaller
groups, and can be represented with the dendrograms in this recipe. There are many different
parameters you can control in the hierarchical cluster analysis process, and there may not be a
single “right” way to do it for your data.
First, we normalized the data using
scale()
with its default settings. You can scale your data
differently, or not at all. (With this data set, notscaling the data will lead to
GDP
overwhelming
the other variables, as shown in
Figure 13-20
.
)
