For ggRandomForests examples and tests, as well as streamlining the
R CMD CHECK for package release, we cache the computationally expensive operations
from the randomForestSRC package.To test the interaction plots, we build a regression randomForest (airq_rf)
with the airquality measurements data, then run the find.interaction function
to determine pairwise variable interaction measures.
The airq_interation "data set" is a cache of the find.interaction function, which
measures pairwise interactions between variables from the airq_rf random
forest model.
The data were from New York, from May to September 1973. The data was obtained from the
New York State Department of Conservation (ozone data) and the National Weather Service
(meteorological data).