spatstat (version 1.55-0)

marks: Marks of a Point Pattern

Description

Extract or change the marks attached to a point pattern dataset.

Usage

marks(x, …)
# S3 method for ppp
marks(x, …, dfok=TRUE, drop=TRUE)           
# S3 method for ppx
marks(x, …, drop=TRUE)
marks(x, …) <- value
# S3 method for ppp
marks(x, …, dfok=TRUE, drop=TRUE) <- value
# S3 method for ppx
marks(x, …) <- 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.

Value

For marks(x), the result is a vector, factor, data frame or hyperframe, containing the mark values attached to the points of x.

For marks(x) <- value, the result is the updated point pattern x (with the side-effect that the dataset x is updated in the current environment).

For setmarks(x,value) and x %mark% value, the return value is the point pattern obtained by replacing the marks of x by value.

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.

See Also

ppp.object, ppx, unmark, hyperframe

Examples

# NOT RUN {
   X <- amacrine
   # extract marks
   m <- marks(X)
   # recode the mark values "off", "on" as 0, 1
   marks(X) <- as.integer(m == "on")
# }