Usage
group_osm_objects(obj = obj, groups = NULL, make_hull = FALSE,
boundary = -1, cols = NULL, col_extra = NULL, colmat = TRUE,
rotate = NULL, lwd = 0)
Arguments
obj
An sp SPDF or SLDF (list of polygons or lines) returned by
extract_osm_objects()
groups
A list of spatial points objects, each of which contains the
coordinates of points defining one group
make_hull
Either a single boolean value or a vector of same length as
groups specifying whether a convex hull should be constructed around the
group (TRUE), or whether they group already defines a hull (convex or
otherwise; FALSE).
boundary
(negative, 0, positive) values define whether the boundary of
groups should (exlude, bisect, include) objects which straddle the precise
boundary. (Has no effect if 'col_extra' is NULL.)
cols
Either a vector of >= 4 colours passed to colour_mat() (if
'colmat=T') to arrange as a 2-D map of visually distinct colours (default
uses rainbow colours), or (if 'colmat=F'), a vector of the same length as
groups specifying individual colours for each.
col_extra
If NULL, then any polygons *NOT* within the convex hulls are
assigned to nearest group and coloured accordingly (and boundary has no
effect); if NOT NULL, then any polygons not within groups are coloured this
colour.
colmat
If TRUE generates colours according to colour_mat(), otherwise
the colours of groups are specified directly by the vector of cols.
rotate
Passed to colour_mat() to rotate colours by the specified
number of degrees clockwise.
lwd
Width of boundary line (0 for no line)
Note
Any group that is entire contained within any other group is assumed to
represent a hole, such that points internal to the smaller contained group
are *excluded* from the group, while those outside the smaller yet inside the
bigger group are included.Warning
Bisecting objects along group boundaries ('boundary=0') can take
considerably longer than simple allocation of objects either side of
boundary.