Compare-methods: Compare Raster* objects

In raster: Geographic Data Analysis and Modeling

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

Example output

Loading required package: sp
NOTE: rgdal::checkCRSArgs: no proj_defs.dat in PROJ.4 shared files
[1] TRUE
NOTE: rgdal::checkCRSArgs: no proj_defs.dat in PROJ.4 shared files
[1] TRUE

raster documentation built on Jan. 5, 2021, 3:01 a.m.