raster: crop – R documentation

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crop

Crop

Description

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

## S4 method for signature 'Raster'
crop(x, y, filename="", snap='near', datatype=NULL, ...)

## S4 method for signature 'Spatial'
crop(x, y, ...)

Arguments

`x`	Raster* object or SpatialPolygons, SpatialLines, or SpatialPoints* 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)
`...`	Additional arguments as for `writeRaster`

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.

To crop by row and column numbers you can create an extent like this (for Raster x, row 5 to 10, column 7 to 12) crop(x, extent(x, 5, 10, 7, 15))

Value

RasterLayer or RasterBrick object; or SpatialLines or SpatialPolygons object.

Note

values within the extent of a Raster* object can be set to NA with mask

Examples

r <- raster(nrow=45, ncol=90)
values(r) <- 1:ncell(r)
e <- extent(-160, 10, 30, 60)
rc <- crop(r, e)	

# use row and column numbers:
rc2 <- crop(r, extent(r, 5, 10, 7, 15))

# crop Raster* with Spatial* object
b <- as(extent(6, 6.4, 49.75, 50), 'SpatialPolygons')
crs(b) <- crs(r)
rb <- crop(r, b)

# crop a SpatialPolygon* object with another one
if (require(rgdal) & require(rgeos)) {
  p <- shapefile(system.file("external/lux.shp", package="raster"))
  pb <- crop(p, b)
}

raster

Geographic Data Analysis and Modeling

v3.4-10

GPL (>= 3)

Authors

Robert J. Hijmans [cre, aut] (<https://orcid.org/0000-0001-5872-2872>), Jacob van Etten [ctb], Michael Sumner [ctb], Joe Cheng [ctb], Dan Baston [ctb], Andrew Bevan [ctb], Roger Bivand [ctb], Lorenzo Busetto [ctb], Mort Canty [ctb], Ben Fasoli [ctb], David Forrest [ctb], Aniruddha Ghosh [ctb], Duncan Golicher [ctb], Josh Gray [ctb], Jonathan A. Greenberg [ctb], Paul Hiemstra [ctb], Kassel Hingee [ctb], Institute for Mathematics Applied Geosciences [cph], Charles Karney [ctb], Matteo Mattiuzzi [ctb], Steven Mosher [ctb], Babak Naimi [ctb], Jakub Nowosad [ctb], Edzer Pebesma [ctb], Oscar Perpinan Lamigueiro [ctb], Etienne B. Racine [ctb], Barry Rowlingson [ctb], Ashton Shortridge [ctb], Bill Venables [ctb], Rafael Wueest [ctb]

Initial release

2021-05-02