is.marked(X, ...)TRUE if X is marked.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.
It is generic; methods are provided
for point patterns (objects of class "ppp")
and point process models (objects of class "ppm").
is.marked.ppp,
is.marked.ppm