ACE: A function to compute Massey Absolute Centralisation Index...
In OasisR: Outright Tool for the Analysis of Spatial Inequalities and Segregation

View source: R/SegFunctions.R

ACE	R Documentation

A function to compute Massey Absolute Centralisation Index (ACE)

Description

The absolute centralization index measures a group spatial distribution compared to the distribution of land area around the city center. The function can be used in two ways: to provide an area vector and a vector containing the distances between spatial units centroids and the central spatial unit or a external geographic information source (spatial object or shape file).

Usage

ACE(x, a = NULL, dc = NULL, center = 1, 
spatobj = NULL, folder = NULL, shape = NULL)

Arguments

`x`	- an object of class matrix (or which can be coerced to that class), where each column represents the distribution of a group within spatial units. The number of columns should be greater than 1 (at least 2 groups are required). You should not include a column with total population, because this will be interpreted as a group.
`a`	- a numeric vector containing spatial unit areas
`dc`	- a numeric vector containing the distances between spatial units centroids and the central spatial unit
`center`	- a numeric value giving the number of the spatial unit that represents the center in the table
`spatobj`	- a spatial object (SpatialPolygonsDataFrame) with geographic information
`folder`	- a character vector with the folder (directory) name indicating where the shapefile is located on the drive
`shape`	- a character vector with the name of the shapefile (without the .shp extension).

Value

a numeric vector containing asolute centralisation index value for each group

References

Massey D. S. and Denton N. A. (1988) The dimensions of residential segregation. Social Forces 67(2), pp. 281-315.

Examples

x <- segdata@data[ ,1:2]
ar<-area(segdata)
distc<- distcenter(segdata, center = 28)
foldername <- system.file('extdata', package = 'OasisR')
shapename <- 'segdata'

ACE(x, a = ar, dc=distc) 

ACE(x, spatobj = segdata, center = 28) 

ACE(x, folder = foldername, shape = shapename, center = 28)

OasisR documentation built on Aug. 30, 2023, 1:09 a.m.