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#Croping a raster in r how to#

We can use the crop() function to crop a raster to the extent of another That the raster layer matches the extent of the desired vector layers. Cropping a raster can also be useful when creating pretty maps so Raster to the extent of our study area to reduce file sizes as we process Sometimes we have a raster file that is much larger than our An elevation surface in GeoTIFF format – greenįrequent use cases of cropping a raster file include reducing file size andĬreating maps.Fish tracking locations (marked with white dots)– black.The graphic below illustrates the extent of several of the spatial layers that Represents the overall geographic coverage of the spatial object. “edge” or location that is the furthest north, south east and west. Spatial extent of a shapefile or R spatial object represents the geographic We often work with spatial layers that have different spatial extents. Within a set of polygons, or in a buffer (surrounding) region around a set of

#Croping a raster in r how to#

We will also cover how to extract values from a raster that occur This episode explains how to crop a raster using the extent of a vector

See the lesson homepage for detailed information about the software,ĭata, and other prerequisites you will need to work through the examples in this episode. Things You’ll Need To Complete This Episode P <- shapefile(system.file("external/lux.Crop a raster to the extent of a vector layer.Įxtract values from a raster that correspond to a vector file overlay. # crop a SpatialPolygon* object with another one Values within the extent of a Raster* object can be set to NA with mask See AlsoĮxtend, merge Examples r <- raster(nrow=45, ncol=90)ī <- as(extent(6, 6.4, 49.75, 50), 'SpatialPolygons') RasterLayer or RasterBrick object or SpatialLines or SpatialPolygons object. 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)

New Extent objects can also be created with function extent and drawExtent by clicking twice on a plot. You can check this with the extent function. Objects from which an Extent can be extracted/created include RasterLayer, RasterStack, RasterBrick and objects of the Spatial* classes from the sp package. Output dataType (by default it is the same as the input datatype) One of 'near', 'in', or 'out', for use with alignExtentĬharacter. Raster* object or SpatialPolygons*, SpatialLines*, or SpatialPoints* objectĮxtent object, or any object from which an Extent object can be extracted (see Details)Ĭharacter. Usage # S4 method for signature 'Raster'Ĭrop(x, y, filename="", snap='near', datatype=NULL. Areas included in y but outside the extent of x are ignored (see extend if you want a larger area). If x is a Raster* object, the Extent is aligned to x.

dimensions: Dimensions of a Raster* objectĬrop returns a geographic subset of an object as specified by an Extent object (or object from which an extent object can be extracted/created).

datasource: Are values in memory and/or on disk?.

cover: Replace NA values with values of other layers.

corLocal: Local correlation coefficient.

coords: Coordinates of the Extent of a Raster object.

Compare-methods: Compare Raster* objects.

compareCRS: Partially compare two CRS objects.

cellsFromExtent: Cells from extent, and vice versa.

cellFrom: Get cell, row, or column number.

boundaries: boundaries (edges) detection.

blockSize: Block size for writing files.

as.matrix: Get a vector, matrix, or array with raster cell values.

as.logical-methods: Change cell values to logical or integer values.

as.list: Create a list of RasterLayer objects.

as.ame: Get a ame with raster cell values, or coerce.

as.character: Character representation of a Raster or Extent object.

Arith-methods: Arithmetic with Raster* objects.

approxNA: Estimate values for cell values that are 'NA' by.animate: Animate layers of a Raster* object.alignExtent: Align an extent (object of class Extent).aggregate: Aggregate raster cells or SpatialPolygons/Lines.