Patterns of Several Types of Points 571
> X <- amacrine
> Y <- split(amacrine)
> Y$on <- rjitter(Y$on, 0.1)
> split(X) <- Y
14.3.3 Inspecting a multitype point pattern
Basic tools for inspecting a multitype point pattern include the me thods for print, summary, plot,
and intensity, together with the interactive plotting c ommand iplot.
If X is a multitype point pattern, plot(X) plots the data using the multitype presen ta tion, with a ll
points displayed in a single win dow, using a different symbol for each type of point. See Figure 14.1.
The m apping o f types to symbols is shown in an explanatory legend, and is also r e turned invisibly
from the plot command as an object of class "symbolmap", allowing the same map ping to be re-
used or modified .