# redwoodfull

##### California Redwoods Point Pattern (Entire Dataset)

These data represent the locations of 195 seedlings and saplings
of California redwood trees in a square sampling region.
They were described and analysed by Strauss (1975).
This is the ``**full**'' dataset; most writers have
analysed a subset extracted by Ripley (1977)
which is available as `redwood`

.
Strauss (1975) divided the sampling region into two subregions I and II
demarcated by a diagonal line. The spatial pattern
appears to be slightly regular in region I and strongly clustered in
region II.

Strauss (1975) writes:

The dataset `redwoodfull`

contains the full point pattern
of 195 trees.
The window has been rescaled to the unit square.
Its physical size is approximately 130 feet across.

The auxiliary information about the subregions is contained in
`redwoodfull.extra`

, which is a list with entries
`rdiag`

The coordinates of the diagonal boundary
between regions I and II
`regionI`

Region I as a window object
`regionII`

Region II as a window object
`regionR`

Ripley's subrectangle (approximate)
`plotit`

Function to plot the full data and auxiliary markings
}

Ripley (1977) extracted a subset of these data, containing 62 points,
lying within a square subregion which overlaps regions I and II.
He rescaled that subset to the unit square.
This subset has been re-analysed many times,
and is the dataset usually known as
``the redwood data'' in the spatial statistics literature.
The exact dataset used by Ripley is supplied in the `redwood`

.

The approximate position of the square chosen by Ripley
within the `redwoodfull`

pattern
is indicated by the window `redwoodfull.extra$regionR`

.
There are some minor inconsistencies with
`redwood`

since it originates from a different digitisation.

##### Usage

`data(redwoodfull)`

##### format

The dataset `redwoodfull`

is an object of class `"ppp"`

representing the point pattern of tree locations.
See `ppp.object`

for details of the format of a
point pattern object.
The window has been rescaled to the unit square.
Its physical size is approximately 128 feet across.

The dataset `redwoodfull.extra`

is a list with entries
`rdiag`

coordinates of endpoints of a line,
in format `list(x=numeric(2),y=numeric(2))`

`regionI`

a window object
`regionII`

a window object
`regionR`

a window object
`plotit`

Function with no arguments
}

##### source

Strauss (1975). The plot of the data published by Strauss (1975) was scanned and digitised by Sandra Pereira, University of Western Australia, 2002.

##### References

Diggle, P.J. (1983)
*Statistical analysis of spatial point patterns*.
Academic Press.

Ripley, B.D. (1977)
Modelling spatial patterns (with discussion).
*Journal of the Royal Statistical Society, Series B*
**39**, 172--212.

Strauss, D.J. (1975)
A model for clustering.
*Biometrika* **63**, 467--475.

##### See Also

##### Examples

```
data(redwoodfull)
plot(redwoodfull)
redwoodfull.extra$plotit()
# extract the pattern in region II
redwoodII <- redwoodfull[, redwoodfull.extra$regionII]
```

*Documentation reproduced from package spatstat, version 1.31-2, License: GPL (>= 2)*