overlay-methods {sp} | R Documentation |
Methods for spatially overlay-ing points (grids) and rings layers
Description
overlay combines points (or grids) and rings by performing point-in-polygon
operation on all point-ring combinations.
Methods
- x = "SpatialPoints", y = "SpatialPolygons"
- returns a numeric vector of length
equal to the number of points; the number is the id (number) of the ring of
y
in which a point falls; NA denotes the point does not fall in a ring; if a point
falls in multiple rings, the last ring is recorded.
- x = "SpatialPointsDataFrame", y = "SpatialPolygons"
- equal to the previous method,
except that an argument
fn=xxx
is allowed, e.g. fn = mean
which will
then report a data.frame with the mean values of the x
points fallin in each
ring (set) of y
- x = "SpatialPolygons", y = "SpatialPoints"
- returns the ring id of points in
y
;
if x
is a SpatialRingDataFrame
, a data.frame with rows from x
corresponding to ponits in y
is returned.
- x = "SpatialGridDataFrame", y = "SpatialPoints"
- returns object of class
SpatialPointsDataFrame with grid attribute values x at spatial
point locations y; NA for NA grid cells or points outside grid, and NA values
on NA grid cells.
- x = "SpatialGrid", y = "SpatialPoints"
- returns grid values x at spatial
point locations y; NA for NA grid cells or points outside the grid
- x = "SpatialPixelsDataFrame", y = "SpatialPoints"
- returns grid values x at
spatial point locations y; NA for NA grid cells or points outside the grid
- x = "SpatialPixels", y = "SpatialPoints"
- returns grid values x at spatial
point locations y; NA for NA grid cells or points outside the grid
Note
points on a ring boundary and points corresponding to a ring vertex are
considered to be inside the ring
Author(s)
Edzer J. Pebesma, e.pebesma@geo.uu.nl
See Also
overlay, point.in.polygon
[Package
sp version 0.7-12
Index]