# duplicated.ppp

##### Determine Duplicated Points in a Spatial Point Pattern

Determines which points in a spatial point pattern are duplicates of previous points, and returns a logical vector.

##### Usage

```
## S3 method for class 'ppp':
duplicated(x, \dots, rule=c("spatstat", "deldir", "unmark"))
``` ## S3 method for class 'ppx':
duplicated(x, \dots)

## S3 method for class 'ppp':
anyDuplicated(x, \dots)

## S3 method for class 'ppx':
anyDuplicated(x, \dots)

##### Arguments

- x
- A spatial point pattern
(object of class
`"ppp"`

or`"ppx"`

). - ...
- Ignored.
- rule
- Character string. The rule for determining duplicated points.

##### Details

These are methods for the generic functions `duplicated`

and `anyDuplicated`

for
point pattern datasets (of class `"ppp"`

, see
`ppp.object`

, or class `"ppx"`

).

`anyDuplicated(x)`

is a faster version of
`any(duplicated(x))`

.

Two points in a point pattern are deemed to be identical if their $x,y$ coordinates are the same, and their marks are also the same (if they carry marks). The Examples section illustrates how it is possible for a point pattern to contain a pair of identical points.

This function determines which points in `x`

duplicate
other points that appeared earlier in the sequence. It
returns a logical vector with entries that are `TRUE`

for duplicated points and `FALSE`

for unique (non-duplicated)
points.

If `rule="spatstat"`

(the default), two points are deemed
identical if their coordinates are equal according to `==`

,
*and* their marks are equal according to `==`

.
This is the most stringent possible test.
If `rule="unmark"`

, duplicated points are
determined by testing equality of their coordinates only,
using `==`

.
If `rule="deldir"`

, duplicated points are
determined by testing equality of their coordinates only,
using the function `duplicatedxy`

in the package `duplicated.data.frame`

. Setting `rule="deldir"`

will ensure consistency with functions in the

##### Value

`duplicated(x)`

returns a logical vector of length equal to the number of points in`x`

.`anyDuplicated(x)`

is a number equal to 0 if there are no duplicated points, and otherwise is equal to the index of the first duplicated point.

##### See Also

##### Examples

```
X <- ppp(c(1,1,0.5), c(2,2,1), window=square(3))
duplicated(X)
duplicated(X, rule="deldir")
```

*Documentation reproduced from package spatstat, version 1.41-1, License: GPL (>= 2)*