redlistr (version 2.1.0)

getAreaChange: Area change between two inputs in km2

Description

getAreaChange reports the difference in area between two inputs. Inputs can be SpatRaster, SpatVector, sf or a data frame of areas and may contain data for multiple ecosystem types. Ensure x and y are the same data type. If using data frame as input, ensure areas are measured in km2

Usage

getAreaChange(x, y, names_from_x = NA, names_from_y = NA)

Value

Returns a table containing ecosystem labels, areas, and the difference in area of the two inputs in km2

Arguments

x

SpatRaster, SpatVector, or sf object representing one or more ecosystems or a data frame with two columns, one of them labeled "area", and the other containing ecosystem labels names_from_x.

y

SpatRaster, SpatVector, or sf object representing one or more ecosystems or a data frame with two columns, one of them labeled "area", and the other containing ecosystem labels names_from_y.

names_from_x

name of column containing ecosystem labels. Ignored if x is a raster.

names_from_y

name of column containing ecosystem labels. Ignored if y is a raster. names_from_x used if not provided.

Author

Nicholas Murray , Calvin Lee , Aniko B. Toth

See Also

Other Change functions: declineForecast(), getArea(), getAreaTrend(), getDeclineStats()

Examples

if (requireNamespace("terra", quietly = TRUE)) {
  ok <- try({
    m1 <- matrix(sample(1:4, 500, replace = TRUE, prob = c(4,1,1,6)), 25, 20)
    r1 <- terra::rast(m1)
    terra::crs(r1) <- "+proj=utm +zone=55 +south +datum=WGS84 +units=m +no_defs"

    m2 <- matrix(sample(1:4, 500, replace = TRUE, prob = c(4,1,1,6)), 25, 20)
    r2 <- terra::rast(m2)
    terra::crs(r2) <- "+proj=utm +zone=55 +south +datum=WGS84 +units=m +no_defs"

    getAreaChange(r1, r2)
  }, silent = TRUE)
}