the object from which to derive the attribute table.
Value
A tibble (or a list of tibbles per layer) of the group attributes of
x.
Details
This table contains at least the column 'gid'.
When this function is called on "ANY" object, it is first tested whether
that object has features (getFeatures), from which the groups
can be reconstructed. If this is not the case, NULL is returned.
# NOT RUN {getGroups(x = gtGeoms$polygon)
# for raster objects, groups are pixels with the same value and their# attributes are in the raster attribute table (RAT)getGroups(x = gtRasters)
# }