Checks whether the argument is an empty window, an empty point pattern, etc.
is.empty(x)
# S3 method for owin
is.empty(x)
# S3 method for ppp
is.empty(x)
# S3 method for psp
is.empty(x)
# S3 method for default
is.empty(x)A window (object of class "owin"),
a point pattern (object of class "ppp"), or
a line segment pattern (object of class "psp").
Logical value.
This function tests whether the object x
represents an empty spatial object, such as an empty window,
a point pattern with zero points, or a line segment pattern
with zero line segments.
An empty window can be obtained as the output of
intersect.owin, erosion,
opening, complement.owin
and some other operations.
An empty point pattern or line segment pattern can be obtained as the result of simulation.