Generic function to test whether a given object (usually a point pattern or something related to a point pattern) has ``marks'' attached to the points which classify the points into several types.
is.multitype(X, …)Object to be inspected
Other arguments.
Logical value, equal to TRUE if X is multitype.
``Marks'' are observations attached to each point of a point pattern.
For example the longleaf dataset
contains the locations of trees, each tree being marked by its diameter;
the amacrine dataset gives the locations of cells
of two types (on/off) and the type of cell may be regarded as a mark attached
to the location of the cell.
Other objects related to point patterns, such as point process models,
may involve marked points.
This function tests whether the object X
contains or involves marked points, and that the
marks are a factor.
For example, the amacrine
dataset is multitype (there are two types of cells, on and off),
but the longleaf dataset is not multitype
(the marks are real numbers).
This function is generic; methods are provided
for point patterns (objects of class "ppp")
and point process models (objects of class "ppm").