Extract Subset of a Layered Object
Extract some or all of the layers of a layered object, or extract a spatial subset of each layer.
## S3 method for class 'layered': [(x, i, j, drop=FALSE, ...)
- A layered object (class
- Subset index for the list of layers. A logical vector, integer vector or character vector specifying which layers are to be retained.
- Subset index to be applied to the data in each layer.
Typically a spatial window (class
- Logical. If
ispecifies only a single layer and
drop=TRUE, then the contents of this layer will be returned.
A layered object represents data that should be plotted in
successive layers, for example, a background and a foreground.
This function extracts a designated subset of a layered object.
It is a method for
[ for the
i specifies which layers will be retained.
It should be a valid subset index for the list of layers.
j will be applied to each layer. It is typically
a spatial window (class
"owin") so that each of the layers
will be restricted to the same spatial region.
j may be any subset index
which is permissible for the
"[" method for each of the layers.
- Usually an object of class
example(layered) L[-2] L[, square(0.5)]