Divide Multidimensional Point Pattern into Sub-patterns
Divides a multidimensional point pattern into several sub-patterns, according to their marks, or according to any user-specified grouping.
## S3 method for class 'ppx' split(x, f = marks(x), drop=FALSE, un=NULL, ...)
x |
A multi-dimensional point pattern.
An object of class |
f |
Data determining the grouping. Either a factor, a logical vector, or the name of one of the columns of marks. |
drop |
Logical. Determines whether empty groups will be deleted. |
un |
Logical. Determines whether the resulting subpatterns will be unmarked (i.e. whether marks will be removed from the points in each subpattern). |
... |
Other arguments are ignored. |
The generic command split allows a dataset to be separated
into subsets according to the value of a grouping variable.
The function split.ppx is a method for the generic
split for the class "ppx" of multidimensional
point patterns. It divides up the points of the point pattern x
into several sub-patterns according to the values of f.
The result is a list of point patterns.
The argument f may be
a factor, of length equal to the number of points in x.
The levels of f
determine the destination of each point in x.
The ith point of x will be placed in the sub-pattern
split.ppx(x)$l where l = f[i].
a character string, matching the name of one of the columns of
marks, if marks(x) is a data frame. This column should
be a factor.
If f is missing, then it will be determined by the
marks of the point pattern. The pattern x can be either
a multitype point pattern
(a marked point pattern whose marks vector is a factor).
Then f is taken to be the marks vector.
The effect is that the points of each type
are separated into different point patterns.
a marked point pattern with a data frame or hyperframe
of marks, containing at least one
column that is a factor. The first such column will be used to
determine the splitting factor f.
Some of the sub-patterns created by the split
may be empty. If drop=TRUE, then empty sub-patterns will
be deleted from the list. If drop=FALSE then they are retained.
The argument un determines how to handle marks
in the case where x is a marked point pattern.
If un=TRUE then the marks of the
points will be discarded when they are split into groups,
while if un=FALSE then the marks will be retained.
If f and un are both missing,
then the default is un=TRUE for multitype point patterns
and un=FALSE for marked point patterns with a data frame of
marks.
The result of split.ppx has class "splitppx"
and "anylist". There are methods for print,
summary and plot.
A list of point patterns.
The components of the list are named by the levels of f.
The list also has the class "splitppx" and "anylist".
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),t=runif(4),
age=factor(rep(c("old", "new"), 2)),
size=runif(4))
X <- ppx(data=df, coord.type=c("s","s","t","m","m"))
X
split(X)Please choose more modern alternatives, such as Google Chrome or Mozilla Firefox.