BOXPLOT Display boxplots of a data sample.
BOXPLOT(X) produces a box and whisker plot with one
box for each column
of X. The boxes have lines at the lower
quartile, median, and upper
quartile values. The whiskers are lines
extending from each end of the
boxes to show the extent of the rest of the
data. Outliers are data
with values beyond the ends of the whiskers.