Plotting the data using lattice

The lattice package is a useful package to learn, especially for analysts who like to work in formula notation (y~x).

In this example, we will run a lattice plot in order to plot Not.Covered.Pct on the y-axis, Year on the x-axis, and produce separate plots by category.

The main call is specified by the following:

xyplot(Not.Covered.Pct ~ Year | cat, data = x3)

Since we are plotting the top 10 groups, we can specify layout=c(5,2) to indicate we want to arrange the 10 plots in a 5*2 matrix. Not.Covered.Pct is to be arranged on the y axis (left side of the ~ sign), and Year is arranged along the x-axis (right side of ~ sign). The bar (|) indicates that the data is to be plotted separately by each category:

library(lattice)
x.tick.number <- 14
at <- seq(1, nrow(x3), length.out = x.tick.number)
labels <- round(seq(1999, 2012, length.out = x.tick.number))

p <- xyplot(Not.Covered.Pct ~ Year | cat, data = x3, type = "l", main = list(label = "Enrollment by...