replacement.RdYou can set values of a Raster* object, when i is a vector of cell numbers, a Raster*, Extent, or Spatial* object.
These are shorthand methods that work best for relatively small Raster* objects. In other cases you can use functions such as calc and rasterize.
x a Raster* object i cell number(s), row number(s), Extent, Spatial* object j columns number(s) (only available if i is (are) a row number(s)) value new cell value(s)