tmap (version 1.6)

crop_shape: Crop shape object

Description

Crop a shape object (from class Spatial-class or Raster).

Usage

crop_shape(x, y, polygon = FALSE, ...)

Arguments

x

shape object, i.e. an object from class Spatial-class or Raster

y

bounding box (2 by 2 matrix), an extent, or a shape object from which the bounding box is extracted (unless polygon is TRUE and x is a SpatialPolygons object).

polygon

should x be cropped by the polygon defined by y. If FALSE (default), x is cropped by the bounding box of x. Polygon cropping only works when x is a spatial object and y is a SpatialPolygons object.

...

arguments passed on to crop

Details

This function is a wrapper around crop from the raster package. It does two things in addition: SpatialGrid objects are allowed, and if y is a shape object with a different projection, it is temporarily reprojected in order to obtain a bounding box by which x is cropped.

See Also

bb

Examples

data(Europe, land, metro)

land_europe <- crop_shape(land, Europe)

qtm(land_europe, raster="trees", style="natural")

metro_europe <- crop_shape(metro, Europe, polygon = TRUE)

qtm(Europe) +
tm_shape(metro_europe) +
	tm_bubbles("pop2010", col="red", title.size="European cities") +
	tm_legend(frame=TRUE)