Data Analysis with R, Second Edition - Second Edition

More than two continuous variables

Finally, there is an excellent way to visualize correlation matrices like the one we saw with the iris dataset in the section, Comparing multiple correlations. To do this, we have to install and load the corrgram package as follows:

 install.packages("corrgram") 
 library(corrgram) 
 
 corrgram(iris, lower.panel=panel.conf, upper.panel=panel.pts) 
 

After installing the corrgram :

Figure 3.13: A corrgram of the iris dataset's continuous variables

With corrgrams, we can exploit the fact that correlation matrices are symmetrical by packing in more information. On the lower left panel, we have the Pearson correlation ...