raster (version 2.3-40)

Compare-methods: Compare Raster* objects

Description

These methods compare the location and resolution of Raster* objects. That is, they compare their spatial extent, projection, and number of rows and columns. For BasicRaster objects you can use == and !=, the values returned is a single logical value TRUE or FALSE For RasterLayer objects, these operators also compare the values associated with the objects, and the result is a RasterLayer object with logical (Boolean) values. The following methods have been implemented for RasterLayer objects: ==, !=, >, <, <=",">=

Value

• A logical value or a RasterLayer object, and in some cases the side effect of a new file on disk.

Examples

r1 <- raster()
r1 <- setValues(r1, round(10 * runif(ncell(r1))))
r2 <- setValues(r1, round(10 * runif(ncell(r1))))
as(r1, 'BasicRaster') == as(r2, 'BasicRaster')
r3 <- r1 == r2

b <- extent(0, 360, 0, 180)
r4 <- setExtent(r2, b)
as(r2, 'BasicRaster') != as(r4, 'BasicRaster')
# The following would give an error. You cannot compare RasterLayer 
# that do not have the same BasicRaster properties.
#r3 <- r1 > r4