# fasp.object

##### Function Arrays for Spatial Patterns

A class `"fasp"`

to represent a ``matrix''
of functions, amenable to plotting as a matrix of plot panels.

- Keywords
- spatial

##### Details

An object of this class is a convenient way of storing (and later plotting, editing, etc) a set of functions $f_{i,j}(r)$ of a real argument $r$, defined for each possible pair $(i,j)$ of indices $1 \le i,j \le n$. We may think of this as a matrix or array of functions $f_{i,j}$.

Function arrays are particularly useful in the analysis of a multitype point pattern (a point pattern in which the points are identified as belonging to separate types). We may want to compute a summary function for the points of type $i$ only, for each of the possible types $i$. This produces a $1 \times m$ array of functions. Alternatively we may compute a summary function for each possible pair of types $(i,j)$. This produces an $m \times m$ array of functions.

For multitype point patterns the command `alltypes`

will compute arrays of summary functions for each possible
type or for each possible pair of types.
For univariate (single-type) point patterns the command
`allstats`

will compute an array of
different summary functions $F$, $G$, $J$,
$K$ for the same dataset.
Both `alltypes`

and `allstats`

return an object of class `"fasp"`

.

There are methods for `plot`

, `print`

and `"["`

in this class.
The plot method displays the entire array of functions.
The method `[.fasp`

selects a sub-array using the natural
indices `i,j`

.

An object of class `"fasp"`

is a list containing at least the
following components:
`which[i,j] = k`

then the function represented by `fns[[k]]`

should be plotted
in the panel at position $(i,j)$. If `which[i,j] = NA`

then nothing is plotted in that position.
}

##### See Also

##### Examples

```
# unmarked point pattern
data(swedishpines)
<testonly># smaller dataset
swedishpines <- swedishpines[1:30]</testonly>
a <- allstats(swedishpines,dataname="Swedish Pines")
a
plot(a)
plot(a[1,])
# multitype point pattern
data(amacrine)
a <- alltypes(amacrine, "G")
plot(a)
# select the row corresponding to cells of type "on"
b <- a["on", ]
plot(b)
```

*Documentation reproduced from package spatstat, version 1.5-9, License: GPL version 2 or newer*