sampleRegular: Regular sample

In raster: Geographic Data Analysis and Modeling

Description

Take a systematic sample from a Raster* object.

Usage

## S4 method for signature 'Raster'
sampleRegular(x, size, ext=NULL, cells=FALSE, xy=FALSE, asRaster=FALSE, 
            sp=FALSE, useGDAL=FALSE, ...)

Arguments

x	Raster object
size	positive integer giving the number of items to choose.
ext	Extent. To limit regular sampling to the area within that box
cells	logical. Also return sampled cell numbers (if asRaster=FALSE)
xy	logical. If TRUE, coordinates of sampled cells are also returned
asRaster	logical. If TRUE, a RasterLayer or RasterBrick is returned, rather than the sampled values
sp	logical. If TRUE, a SpatialPointsDataFrame is returned
useGDAL	logical. If TRUE, GDAL is used to sample in some cases. This is quicker, but can result in values for a different set of cells than when useGDAL=FALSE. Only for rasters that are accessed via rgdal, and are not rotated. When TRUE arguments cells, xy, and sp are ignored (i.e., FALSE
...	additional arguments. None implemented

Value

A vector (single layer object), matrix (multi-layered object; or if cells=TRUE, or xy=TRUE), Raster* object (if asRaster=TRUE), or SpatialPointsDataFrame (if sp=TRUE)

See Also

sampleRandom, sampleStratified

Examples

 r <- raster(system.file("external/test.grd", package="raster"))
 v <- sampleRegular(r, size=100)
 x <- sampleRegular(r, size=100, asRaster=TRUE)

Example output

Loading required package: sp

raster documentation built on Jan. 5, 2021, 3:01 a.m.