chopin (version 0.9.4)

summarize_aw: Area weighted summary using two polygon objects

Description

When x and y are different classes, poly_weight will be converted to the class of x.

Usage

summarize_aw(x, y, ...)
# S4 method for SpatVector,SpatVector
summarize_aw(
  x,
  y,
  target_fields = NULL,
  id_x = "ID",
  fun = stats::weighted.mean,
  extent = NULL,
  ...
)
# S4 method for character,character
summarize_aw(
  x,
  y,
  target_fields = NULL,
  id_x = "ID",
  fun = stats::weighted.mean,
  out_class = "terra",
  extent = NULL,
  ...
)
# S4 method for sf,sf
summarize_aw(
  x,
  y,
  target_fields = NULL,
  id_x = "ID",
  fun = NULL,
  extent = NULL,
  ...
)

Value

A data.frame with all numeric fields of area-weighted means.

Arguments

x

A sf/SpatVector object or file path of polygons detectable with GDAL driver at weighted means will be calculated.

y

A sf/SpatVector object or file path of polygons from which weighted means will be calculated.

...

Additional arguments depending on class of x and y.

target_fields

character. Field names to calculate area-weighted.

id_x

character(1). The unique identifier of each polygon in x. Default is "ID".

fun

function(1)/character(1). The function to calculate the weighted summary. Default is stats::weighted.mean. The function must have a w argument. If both x and y are sf, it should be one of c("sum", "mean"). It will determine extensive argument in sf::st_interpolate_aw.

extent

numeric(4) or SpatExtent object. Extent of clipping x. It only works with x of character(1) file path. See terra::ext for more details. Coordinate systems should match.

out_class

character(1). "sf" or "terra". Output class.

Author

Insang Song

See Also

Other Macros for calculation: extract_at(), kernelfunction(), summarize_sedc()

Examples

lastpar <- par(mfrow = c(1, 1))
# package
library(sf)
options(sf_use_s2 = FALSE)
nc <- sf::st_read(system.file("shape/nc.shp", package="sf"))
nc <- sf::st_transform(nc, "EPSG:5070")
pp <- sf::st_sample(nc, size = 300)
pp <- sf::st_as_sf(pp)
pp[["id"]] <- seq(1, nrow(pp))
sf::st_crs(pp) <- "EPSG:5070"
ppb <- sf::st_buffer(pp, nQuadSegs=180, dist = units::set_units(20, "km"))

suppressWarnings(
  ppb_nc_aw <-
    summarize_aw(
      ppb, nc, c("BIR74", "BIR79"),
      "id", fun = "sum"
    )
)
summary(ppb_nc_aw)

# terra examples
library(terra)
ncpath <- system.file("gpkg/nc.gpkg", package = "sf")
nc <- terra::vect(ncpath)
pp <- terra::spatSample(nc, size = 300)
pp[["id"]] <- seq(1, nrow(pp))
ppb <- terra::buffer(pp, 20000)

suppressWarnings(
  ppb_nc_aw <-
    summarize_aw(
      ppb, nc, c("BIR74", "BIR79"), "id",
      fun = sum
    )
)
summary(ppb_nc_aw)
par(lastpar)