# 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)
## S3 method for class 'ppx':
marks(x, \dots, drop=TRUE)
marks(x, ...) <- value
## S3 method for class 'ppp':
marks(x, \dots, dfok=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
- 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`

.

##### 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")
```

*Documentation reproduced from package spatstat, version 1.20-1, License: GPL (>= 2)*