# 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"))
```

##### Arguments

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

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

##### Details

This is a method for the generic function `duplicated`

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

, see `ppp.object`

).

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), duplicated points are
determined by testing equality of their coordinates and marks
using `==`

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

, duplicated points are
determined using the function `duplicatedxy`

in the package `duplicated.data.frame`

. Setting `rule="deldir"`

will ensure consistency with functions in the

##### Value

- A logical vector of length equal to the number of points in
`x`

.

##### 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 1.31-3, License: GPL (>= 2)*