raster (version 1.7-23)

indexing: Extract or replace cell values of a Raster object

Description

These are shorthand methods that call other methods that should normally be used, such as getValues, extract, crop, rasterize. object[i] can be used to access values of a Raster* object, using cell numbers. You can also use row and column numbers as index, using object[i,j] or object[i,] or object[,j]. In addition you can supply a SpatialPolygons, SpatialLines or SpatialPoints object. If drop=TRUE (the default) cell values are returned (a vector for a RasterLayer, a matrix for a RasterStack or RasterBrick). If drop=FALSE a Raster* object is returned that has the extent covering the requested cells, and with all other non-requested cells within this extent set to NA. If you supply a RasterLayer, its values will be used as logical (TRUE/FALSE) indices if both Raster objects have the same extent and resolution; otherwise the cell values within the extent of the RasterLayer are returned. You can also set values of a RasterLayer object, when i is a vector of cell numbers or a Spatial* object. Double brackes '[[ ]]' can be used to extract one or more layers from a multi-layer object.

Methods

Get values x[i] x[i,j] Arguments rll{ x a Raster* object i cell number(s), row number(s), a (logical) RasterLayer, Spatial* object j column number(s) (only available if i is (are) a row number(s)) drop If TRUE, cell values are returned. Otherwise, a Raster* object is returned } Set values x[i] <- value x[i,j] <- value Arguments rll{ x a RasterLayer object i cell number(s), row number(s), Extent, Spatial* object j columns number(s) (only available if i is (are) a row number(s)) value new cell value(s) }

See Also

getValues, setValues, extract, crop, rasterize

Examples

r <- raster(ncol=10, nrow=5)
r[] <- 1:ncell(r) * 2
r[1,] <- 1
r[,1] <- 2
r[1,1] <- 3

as.matrix(r)

r[1]
r[1:10]
r[1,]
r[,1]
r[1:2, 1:2]

s <- stack(r, sqrt(r))
s[1:3]
s[[2]]