Usage
## S3 method for class 'Raster':
shift(object, x=0, y=0, filename='', ...)
## S3 method for class 'SpatialPolygons':
shift(object, x=0, y=0, ...)
## S3 method for class 'SpatialLines':
shift(object, x=0, y=0, ...)
## S3 method for class 'SpatialPoints':
shift(object, x=0, y=0, ...)