EDfunc: A function to compute environmental dissimilarity index

Description

Environmental Dissimilarity index measures the dissimilarity between the distribution of a population group x and the one of an environmental (dis-)amenity a among spatial units. The environmental dissimilarity index has several versions: "standard" aspatial version based on Duncan & Duncan (1955) segregation index; adjusted versions with spatial interactions matrices based on contiguities (Morrill, 1991; Tivadar, 2019), boundaries, or shapes (Wong, 1998; Tivadar, 2019); or defined by the user.

Usage

EDfunc (x, a, vers = "standard", w = NULL, ar = NULL, per = NULL,
b = NULL, folder = NULL, shape = NULL, spatobj = NULL, queen = TRUE,
ptype = "int", K = 1, f = "exp", beta = 1)

Value

The value of the environmental dissimilarity index

Arguments

x: - a vector of the population/group distribution across spatial units
a: - a vector of the environmental variable spatial distribution
vers: - the index version: "standard" (by default) for aspatial environmental dissimilarity index (Duncan); "contig" for adjusted index with a contiguity spatial interactions matrix (Morrill); "bound" for adjusted index with a boundaries spatial interactions matrix (Wong); "shape" for adjusted index with a boundaries and shape spatial interactions matrix (Wong); "user" for adjusted index with any user spatial interactions matrix
w: - an optional spatial weights matrix. If necessary and not provided, it will be computed in the function
ar: - an optional vector of spatial units area. If necessary and not provided, it will be computed in the function
per: - an optional vector of spatial units perimeter. If necessary and not provided, it will be computed in the function.
b: - an optional shared border matrix. If necessary and not provided, it will be computed in the function.
folder: - a character vector with the folder (directory) name indicating where the shapefile with geographical info is located on the drive if the interactions matrix is computed in the function
shape: - a character vector with the name of the shapefile (without the .shp extension)
spatobj: - a spatial object (SpatialPolygonsDataFrame) with geographic information as alternative for the shapefile, if the interactions matrix is computed in the function
queen: - logical parameter defining criteria used for contiguity matrix computation, TRUE for queen (by default), FALSE for rook
ptype: - a string variable giving two options for perimeter calculation for Wong's indices: "int" to use only interior borders of spatial units and "all" to use entire borders, including to the exterior of the area
K: - the order of contiguity matrix if "contig" version is chosen (K = 1 by default)
f: - spatial decay function of contiguity matrix when K > 1, with f = "exp" (by default) for exponential function of contiguity "distance" exp(beta*(1-k))
beta: - spatial decay intensity parameter (equal to 1 by default), used only when the version with contiguity is chosen and K > 1

References

Schaeffer Y. and Tivadar M. (2019) Measuring Environmental Inequalities: Insights from the Residential Segregation Literature. Ecological Economics, 164, 106329

Tivadar M. (2019) OasisR: An R Package to Bring Some Order to the World of Segregation Measurement. Journal of Statistical Software, 89 (7), pp. 1-39

Duncan O. D. and Duncan B. (1955) Residential Distribution and Occupational Stratification. American Journal of Sociology, 60 (5), pp. 493-503

Morrill B. (1991) On the measure of geographic segregation. Geography research forum, 11, pp. 25-36.

Wong D. W. S. (1998) Measuring multiethnic spatial segregation. Urban Geography, 19 (1), pp. 77-87.

Examples

Run this code

data(segdata, package = "OasisR")
# segdata - theoretical distributions on a 10x10 grid map
# We consider A1 - population distribution and A2 - amenity distribution
EDfunc (segdata@data$A1, segdata@data$A2)
EDfunc (segdata@data$A1, segdata@data$A2, vers = "contig", spatobj =segdata, queen = FALSE)
EDfunc (segdata@data$A1, segdata@data$A2, vers = "contig", spatobj =segdata, queen = FALSE, K = 3)
EDfunc (segdata@data$A1, segdata@data$A2, vers = "bound", spatobj =segdata)
EDfunc (segdata@data$A1, segdata@data$A2, vers = "shape", spatobj =segdata, ptype = 'all')