These are methods for extracting and replacing subsets
for the class "solist".
The argument x should be an object of class "solist"
representing a list of two-dimensional spatial objects.
See solist.
For the subset method, the subset index i can be either
a vector index (specifying some elements of the list)
or a spatial window (specifying a spatial sub-region).
For the replacement "[<-" method,
i must be a vector index and value must be a list
of spatial objects;
the designated elements of x will be
replaced by the corresponding elements of the list value.
For the replacement "[[<-" method,
i must be a single integer, and value must be a spatial
object.
If all entries of x belong to the same class,
then in the replacement methods, a value of NA
is automatically coerced to an NA object of the same class.