Extract or change the marks attached to
a line segment pattern.
Usage
"marks"(x, ..., dfok=TRUE)
"marks"(x, ...) <- value
Arguments
x
Line segment pattern dataset (object of class "psp").
...
Ignored.
dfok
Logical. If FALSE, data frames of marks are not permitted
and will generate an error.
value
Vector or data frame of mark values,
or NULL.
Value
For marks(x), the result is a vector, factor or data frame,
containing the mark values attached to the line segments of x.
If there are no marks, the result is NULL.For marks(x) <- value, the result is the updated line segment pattern
x (with the side-effect that the dataset x is updated in
the current environment).
Details
These functions extract or change the marks
attached to each of the line segments in the pattern x.
They are methods for the generic functions
marks and marks<-
for the class "psp" of line segment patterns.
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 marks can be a vector, a factor, or a data frame.
For the assignment marks(x) <- value, the value
should be a vector or factor of length equal to the number of
segments in x, or a data frame with as many rows
as there are segments in x. If value is a single value,
or a data frame with one row, then it will be replicated
so that the same marks will be attached to each segment.
To remove marks, use marks(x) <- NULL or unmark(x).