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:
- fns
{
A list of data frames, each representing one of the functions.
}
- which
{
A matrix representing the spatial arrangement of the
functions. If 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.
}
- titles
{
A list of character strings, providing suitable plotting titles
for the functions.
}
- default.formulae
{
A list of default formulae for plotting each of the functions.
}
- title
{
A character string, giving a default title for the array
when it is plotted.
}