We have just discovered one type of plot in lattice as well as multipanel conditioning. Lattice is a rich package which features diverse plots. We have already encountered the multi-paneled scatterplot obtained using xyplot(). We will have a look at some more lattice multi-paneled graphs in this section: histograms, stacked bars, dotplots, as well as a customization of the scatterplot, where points are replaced by text.
In the previous chapter, we examined the overall distribution of an attribute using the hist() function. The distribution of some measures can vary between groups, that is, it can be more or less skewed in some groups compared to others. The histogram() function in the lattice package allows for a visual inspection of this. We will examine variability in temperatures by month using the airquality dataset. This dataset has six attributes (Ozone, Solar.R, Wind, Temp, Month, and Day), of which you will find a description by typing:
?airquality...
