marks
Marks of a Point Pattern
Extract or change the marks attached to a point pattern dataset.
Usage
marks(x, ...)## S3 method for class 'ppp':
marks(x, \dots, dfok=TRUE, drop=TRUE)
## S3 method for class 'ppx':
marks(x, \dots, drop=TRUE)
marks(x, ...) <- value
## S3 method for class 'ppp':
marks(x, \dots, dfok=TRUE, drop=TRUE) <- value
## S3 method for class 'ppx':
marks(x, \dots) <- value
setmarks(x, value)
x %mark% value
Arguments
- x
- Point pattern dataset (object of class
"ppp"
or"ppx"
). - ...
- Ignored.
- dfok
- Logical. If
FALSE
, data frames of marks are not permitted and will generate an error. - drop
- Logical. If
TRUE
, a data frame consisting of a single column of marks will be converted to a vector or factor. - value
- Replacement value. A vector, data frame or hyperframe of mark values,
or
NULL
.
Details
These functions extract or change the marks
attached to the points of the point pattern x
.
The expression marks(x)
extracts the marks of x
.
The assignment marks(x) <- value
assigns new marks to the
dataset x
, and updates the dataset x
in the current
environment. The expression setmarks(x,value)
or equivalently x %mark% value
returns a point pattern
obtained by replacing the marks of x
by value
, but does
not change the dataset x
itself.
For point patterns in two-dimensional space (objects of class
"ppp"
) the marks can be a vector, a factor, or a data frame.
For general point patterns (objects of class "ppx") the
marks can be a vector, a factor, a data frame or a
hyperframe.
For the assignment marks(x) <- value
, the value
should be a vector or factor of length equal to the number of
points in x
, or a data frame or hyperframe with as many rows
as there are points in x
. If value
is a single value,
or a data frame or hyperframe with one row, then it will be replicated
so that the same marks will be attached to each point.
To remove marks, use marks(x) <- NULL
or
unmark(x)
.
Use ppp
or ppx
to create point patterns in more general
situations.
Value
- For
marks(x)
, the result is a vector, factor, data frame or hyperframe, containing the mark values attached to the points ofx
.For
marks(x) <- value
, the result is the updated point patternx
(with the side-effect that the datasetx
is updated in the current environment).For
setmarks(x,value)
andx %mark% value
, the return value is the point pattern obtained by replacing the marks ofx
byvalue
.
See Also
Examples
data(amacrine)
# extract marks
m <- marks(amacrine)
# recode the mark values "off", "on" as 0, 1
marks(amacrine) <- as.integer(m == "on")