R: Marks of a Point Pattern

marks {spatstat.geom} | R Documentation

## Marks of a Point Pattern

### Description

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

### Usage

    marks(x, ...)

    ## S3 method for class 'ppp'
    marks(x, ..., dfok=TRUE, drop=TRUE)

    ## S3 method for class 'ppx'
    marks(x, ..., drop=TRUE)

    marks(x, ...) <- value

    ## S3 replacement method for class 'ppp'
    marks(x, ..., dfok=TRUE, drop=TRUE) <- value

    ## S3 replacement method for class '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`.

### 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 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`.

### Author(s)

Adrian Baddeley Adrian.Baddeley@curtin.edu.au, Rolf Turner r.turner@auckland.ac.nz and Ege Rubak rubak@math.aau.dk

### See Also

`ppp.object`, `ppx`, `unmark`, `hyperframe`

### Examples

       X <- amacrine
       # extract marks
       m <- marks(X)
       # recode the mark values "off", "on" as 0, 1
       marks(X) <- as.integer(m == "on")

[Package spatstat.geom version 2.2-0 Index]