| acc {lctools} | R Documentation |
Spatial Interaction Models: Destination Accessibility
Description
Destination accessibility or centrality or competition is a variable that when added to a destination choice model forms the competing destinations choice model. A simple formula for this variable is:
A_j = \Sigma ( W_m / D_{jm} ) | m<>j
where A_j is the potential accessibility of destination j to all other potential destinations m, W_m is a weight generally measured by population, and D_{jm} is the distance between j and m.
Usage
acc(X, Y, Pop, Power=1)
Arguments
X |
a numeric vector of x coordinates |
Y |
a numeric vector of y coordinates |
Pop |
a numeric vector of the weights, usually a population variable |
Power |
a power of the distance; default is 1 |
Value
AccMeasure |
a single column numeric matrix of accessibility scores |
Note
X,Y should be Cartesian coordinates for the distances to be measured in meters. In the sample dataset GR.Municipalities the projection used is the EPSG:2100 (GGRS87 / Greek Grid)
Author(s)
Stamatis Kalogirou <stamatis@lctools.science>
References
Kalogirou, S. (2003) The Statistical Analysis and Modelling of Internal Migration Flows within England and Wales, PhD Thesis, School of Geography, Politics and Sociology, University of Newcastle upon Tyne, UK. https://theses.ncl.ac.uk/jspui/handle/10443/204
Kalogirou, S. (2016) Destination Choice of Athenians: an application of geographically weighted versions of standard and zero inflated Poisson spatial interaction models, Geographical Analysis, 48(2),pp. 191-230. DOI: 10.1111/gean.12092 https://onlinelibrary.wiley.com/doi/abs/10.1111/gean.12092
Examples
data(GR.Municipalities)
attr<-GR.Municipalities@data
aMeasure<-acc(attr$X[1:100], attr$Y[1:100],attr$PopTot01[1:100],1)