Compute a kernel smoothed intensity function for each of the components of a split point pattern, or each of the point patterns in a list.

```
# S3 method for splitppp
density(x, …, weights=NULL, se=FALSE)
``` # S3 method for ppplist
density(x, …, weights=NULL, se=FALSE)

x

Split point pattern (object of class `"splitppp"`

created by `split.ppp`

) to be smoothed.
Alternatively a list of point patterns,
of class `"ppplist"`

.

…

Arguments passed to `density.ppp`

to control
the smoothing, pixel resolution, edge correction etc.

weights

Numerical weights for the points. See Details.

se

Logical value indicating whether to compute standard errors as well.

A list of pixel images (objects of class `"im"`

)
which can be plotted or printed;
or a list of numeric vectors giving the values at specified points.

If `se=TRUE`

, the result is a list with two elements named
`estimate`

and `SE`

, each of the format described above.

This is a method for the generic function `density`

.

The argument `x`

should be a list of point patterns,
and should belong to one of the classes
`"ppplist"`

or `"splitppp"`

.

Typically `x`

is obtained by applying
the function `split.ppp`

to a point pattern `y`

by calling `split(y)`

. This splits the points of `y`

into several
sub-patterns.

A kernel estimate of the intensity function of each of the
point patterns is computed using `density.ppp`

.

The return value is usually a list, each of whose entries is a
pixel image (object of class `"im"`

). The return value
also belongs to the class `"solist"`

and can be plotted
or printed.

If the argument `at="points"`

is given, the result is a list
of numeric vectors giving the intensity values at the data points.

If `se=TRUE`

, the result is a list with two elements named
`estimate`

and `SE`

, each of the format described above.

The argument `weights`

specifies numerical case weights
for the data points.
Normally it should be a list, with the same length as
`x`

. The entry `weights[[i]]`

will determine the
case weights for the pattern `x[[i]]`

, and may be given in
any format acceptable to `density.ppp`

.
For example, `weights[[i]]`

can be
a numeric vector of length equal to `npoints(x[[i]])`

,
a single numeric value, a numeric matrix,
a pixel image (object of class `"im"`

),
or an `expression`

.

For convenience, `weights`

can also be a single `expression`

or a single pixel image (object of class `"im"`

).

# NOT RUN { Z <- density(split(amacrine), 0.05) plot(Z) # }