ISMorrillK: A function to compute K-th order Morrill's segregation index

In OasisR: Outright Tool for the Analysis of Spatial Inequalities and Segregation

A function to compute K-th order Morrill's segregation index

Description

This function computes an adaptation of Morrill's segregation index which takes into account the interactions between spatial units defined by K-th ordered contiguity matrix. The index can be used in two ways: to provide a contiguity units defined by K order contiguity matrix. The function can be used in two matrix or a external geographic information source (spatial object or shape file).

Usage

ISMorrillK(x, ck = NULL, queen = FALSE, spatobj = NULL, folder = NULL, 
shape = NULL, K = 2, f = 'exp', beta = 1, prec = 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 greaterTR 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.
ck	a list containing contiguity matrices coresponding to each order (from 1 to K)
queen	logical parameter defining criteria used for contiguity matrix computation, TRUE for queen, FALSE (by default) for rook
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 driveis located.
shape	a character vector with the name of the shapefile (without the .shp extension).
K	the order of the contiguity matrix
f	the distance function, f = 'exp' (by default) for negative exponential function and f = 'rec' for reciprocal function
beta	distance decay parameter
prec	precision parameter. If not NULL, the function stop computing the spatial interaction when the impact on the indice is bellow 10 ^ (-prec)

Value

A numeric vector containing Generalized Morrill's segregation index values for each group

References

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

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

See Also

One-group evenness indices: ISDuncan, Gini, Gorard, HTheil, Atkinson, 'ISWong, ISMorrill

Between groups dissimilarity indices: DIDuncan, Gini2, DIMorrill, DIMorrillK, DIWong

Examples

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

ISMorrillK(x, spatobj = segdata, queen = FALSE, K = 3)

ISMorrillK(x, folder = foldername, shape = shapename, K = 4, f = 'rec') 

OasisR documentation built on April 3, 2025, 5:58 p.m.