Extract Subset of Multidimensional Point Pattern
Extract a subset of a multidimensional point pattern.
## S3 method for class 'ppx' x[i, drop=FALSE, clip=FALSE, ...]
x |
A multidimensional point pattern (object of class |
i |
Subset index. A valid subset index in the usual R sense,
indicating which points should be retained;
or a spatial domain of class |
drop |
Logical value indicating whether to remove unused levels of the marks, if the marks are a factor. |
clip |
Logical value indicating how to form the domain of the resulting
point pattern, when |
... |
Ignored. |
This function extracts a designated subset of a multidimensional point pattern.
The function [.ppx is a method for [ for the
class "ppx". It extracts a designated subset of a point pattern.
The argument i may be either
a subset index in the usual R sense:
either a numeric vector
of positive indices (identifying the points to be retained),
a numeric vector of negative indices (identifying the points
to be deleted) or a logical vector of length equal to the number of
points in the point pattern x. In the latter case,
the points (x$x[i], x$y[i]) for which
subset[i]=TRUE will be retained, and the others
will be deleted.
a spatial domain of class "boxx" or "box3".
Points falling inside this region will be retained.
The argument drop determines whether to remove
unused levels of a factor, if the point pattern is multitype
(i.e. the marks are a factor) or if the marks are a data frame or hyperframe
in which some of the columns are factors.
Use the function unmark to remove marks from a
marked point pattern.
A multidimensional point pattern (of class "ppx").
Adrian Baddeley Adrian.Baddeley@curtin.edu.au, Rolf Turner r.turner@auckland.ac.nz and Ege Rubak rubak@math.aau.dk
df <- data.frame(x=runif(4),y=runif(4),z=runif(4))
X <- ppx(data=df, coord.type=c("s","s","t"))
X[-2]
Y <- ppx(coords(cells), domain = boxx(c(0,1),c(0,1)))
dom <- shift(domain(Y), vec = c(.5,.5))
Y[dom]
Y[dom, clip=TRUE]Please choose more modern alternatives, such as Google Chrome or Mozilla Firefox.