# superimpose

##### Superimpose Several Point Patterns

Superimpose any number of point patterns.

##### Usage

`superimpose(..., W=NULL, check=TRUE)`

##### Arguments

- ...
- Any number of arguments, each of which represents a point pattern.
Each argument must be either a point pattern
object (of class
`"ppp"`

) or a structure containing elements`x`

and`y`

. - W
- Optional. Window for the resulting point pattern.
An object of class
`"owin"`

, or something acceptable to`as.owin`

. - check
- Logical value (passed to
`ppp`

) determining whether to check the geometrical validity of the resulting point pattern.

##### Details

This function is used to superimpose two or more point patterns
(see also `concatxy`

).
Each of the arguments in
`...`

is either a point pattern object (of class `"ppp"`

)
or a structure containing (at least) the elements
`x`

and `y`

. The point patterns are not required to have
the same window of observation.

The window for the superimposed point pattern is
specified by `W`

. Its default value is
the union of the windows of all the point patterns.

If any of the arguments is a *marked* point pattern,
then all of them must be.
In that case, the result is also a marked point pattern.

If the arguments are given in the form `name=value`

,
then the names will be used
as marks attached to the corresponding points. See the last line
in the Examples.

##### Value

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

) representing the superposition (union) of all the point patterns.

##### See Also

See `superimposePSP`

for superimposing patterns of line segments.

##### Examples

```
dat <- runifrect(30)
xy <- list(x=runif(10),y=runif(10))
new <- superimpose(dat, xy)
plot(new)
# how to make a 2-type point pattern with types "a" and "b"
u <- superimpose(a = rpoispp(10), b = rpoispp(20))
# how to make a 2-type point pattern with types 1 and 2
u <- superimpose("1" = rpoispp(10), "2" = rpoispp(20))
```

*Documentation reproduced from package spatstat, version 1.17-1, License: GPL (>= 2)*