Fulltext

Testing spatial autocorrelation in weighted networks: the modes permutation test

Bavaud, François

In: Journal of Geographical Systems, 2013, vol. 15, no. 3, p. 233-247

Ajouter à la liste personnelle
    Titre
    • Testing spatial autocorrelation in weighted networks: the modes permutation test
    Auteur
    • Bavaud, François. Department of Computer Science and Mathematical Methods, Department of Geography, University of Lausanne, Lausanne, Switzerland
    Type de document
    • Postprint
    Langue
    • Anglais
    Publié dans
    • Journal of Geographical Systems, 2013, vol. 15, no. 3, p. 233-247. Springer-Verlag
    Autre version électronique
    Identifiant OAI-PMH
    • oai:doc.rero.ch:322532
    Summary
    In a weighted spatial network, as specified by an exchange matrix, the variances of the spatial values are inversely proportional to the size of the regions. Spatial values are no more exchangeable under independence, thus weakening the rationale for ordinary permutation and bootstrap tests of spatial autocorrelation. We propose an alternative permutation test for spatial autocorrelation, based upon exchangeable spatial modes, constructed as linear orthogonal combinations of spatial values. The coefficients obtain as eigenvectors of the standardized exchange matrix appearing in spectral clustering and generalize to the weighted case the concept of spatial filtering for connectivity matrices. Also, two proposals aimed at transforming an accessibility matrix into an exchange matrix with a priori fixed margins are presented. Two examples (inter-regional migratory flows and binary adjacency networks) illustrate the formalism, rooted in the theory of spectral decomposition for reversible Markov chains