DIMorrillK: A function to compute K-th order Morrill's dissimilarity...

Description Usage Arguments Value References See Also Examples

View source: R/SegFunctions.R

Description

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

Usage

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DIMorrillK(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 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.

ck

- a list with contiguity matrix for each order (from 1 to K)

queen

- logical parameter difining 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 drive

shape

- a character vector with the name of the shapefile (without the .shp extension) .

K

- contiguity matrix order

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 matrix with Generalized Morrill's dissimilarity index values

References

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

See Also

Other one-group evenness indices: ISDuncan, Gini, Gorard, Atkinson, HTheil, ISWong, ISMorrill, ISMorrillK

Between groups dissimilarity indices: DIDuncan, DIMorrill, DIWong

Examples

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

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

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

OasisR documentation built on July 2, 2020, 3:14 a.m.

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