union {raster} | R Documentation |
Extent objects: Objects are combined into their union. See crop
and extend
to union a Raster object with an Extent object.
Two SpatialPolygons* objects. Overlapping polygons (between layers, not within layers) are intersected, other spatial objects are appended. Tabular attributes are joined.
Single SpatialPolygons* object. Overlapping polygons are intersected. Original attributes are lost. New attributes allow for determining how many, and which, polygons overlapped.
## S4 method for signature 'Extent,Extent' union(x, y) ## S4 method for signature 'SpatialPolygons,SpatialPolygons' union(x, y) ## S4 method for signature 'SpatialPolygons,missing' union(x, y)
x |
Extent or SpatialPolygons* object |
y |
Same as |
Extent or SpatialPolygons object
merge
for merging a data.frame with attributes of Spatial objects
and +,SpatialPolygons,SpatialPolygons-method
for an algebraic notation
e1 <- extent(-10, 10, -20, 20) e2 <- extent(0, 20, -40, 5) union(e1, e2) #SpatialPolygons if (require(rgdal) & require(rgeos)) { p <- shapefile(system.file("external/lux.shp", package="raster")) p0 <- aggregate(p) b <- as(extent(6, 6.4, 49.75, 50), 'SpatialPolygons') projection(b) <- projection(p) u <- union(p0, b) plot(u, col=2:4) }