crop returns a geographic subset of an object as specified by an Extent object (or object from which an extent object can be extracted/created).
If x is a Raster* object, the Extent is aligned to x. Areas included in y but outside the extent of x are ignored (see extend if you want a larger area)
Usage
## S3 method for class 'Raster':
crop(x, y, filename="", snap='near', datatype=NULL, ...)
Arguments
x
Raster* object
y
Extent object, or any object from which an Extent object can be extracted (see Details)
filename
Character, output filename. Optional
snap
Character. One of 'near', 'in', or 'out', for use with alignExtent
datatype
Character. Output dataType (by default it is the same as the input datatype)
RasterLayer or RasterBrick object; or SpatialLines or SpatialPolygons object.
Details
Objects from which an Extent can be extracted/created include RasterLayer, RasterStack, RasterBrick and objects of the Spatial* classes from the sp package. You can check this with the extent function. New Extent objects can be also be created with function extent and drawExtent by clicking twice on a plot.