pixelArea {ecotrends}R Documentation

Average pixel area

Description

This function uses the terra::cellSize() function to compute (and optionally map) the area covered by each (optionally non-NA) pixel in a raster map; and then it computes either the mean or the centroid pixel area in that map, for an idea of pixel size in that region. Pixel size can vary widely across latitudes, especially in unprojected longitude-latitude rasters, but also in rasters projected to other non-equal-area coordinate reference systems.

Usage

pixelArea(
  rast,
  type = "mean",
  unit = "m",
  mask = TRUE,
  map = TRUE,
  verbosity = 2
)

Arguments

rast

SpatRaster for which to compute the pixel area

type

character value indicating whether the output value should be the "mean" (default) or "centroid" pixel area

unit

numeric value indicating the units for the output value: either "m" (default) or "km" squared.

mask

logical value (default TRUE) indicating whether to consider only the areas of non-NA pixels

map

logical value (default TRUE) indicating whether to also plot a map

verbosity

integer value indicating the amount of messages to display. The default is 2, for the maximum number of messages available.

Value

numeric value

Author(s)

A. Marcia Barbosa, wrapping 'terra' functions by Robert H. Hijmans

See Also

terra::cellSize(), which this function wraps

Examples

r <- terra::rast(system.file("ex/elev.tif", package = "terra"))

pixelArea(r)

pixelArea(r, unit = "km")

[Package ecotrends version 1.1 Index]