University of Southampton OCS (beta), CAA 2012

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A new method of spatial analysis based on the extraction of proximity graphs
Diego Jimenez

Last modified: 2011-12-16


This paper presents an exploratory method of spatial analysis oriented to the recognition of adjacency patterns in archaeological contexts. The underpinning elements of such method are the relative neighbourhood concept, the retrieval of proximity graphs, the measurement of graph-theoretic relational properties, both at global and local levels; and the visualisation of spatial patterns in three dimensions. This is called Relative Neighbourhood Method of Spatial Analysis, or RN-Method, for short.

The method was specifically designed to analyse a special type of archaeological deposit, which we call ‘spatial symbolic contexts.’ Spatial symbolic contexts are artefact arrangements ordered in such a way that the literal significance of each item acquires a parallel meaning thanks to its spatial associations with other elements of the set.

These appear frequently as a subject of study in archaeology. The paper focuses on the interesting case of Aztec offerings. These archaeological deposits contain a great diversity of ritual objects. The specific arrangement of the items responded to Aztec religious beliefs, whose decipherement is of great relevance for the understanding of that culture.

The RN-Method provides formal means to explore the topology of such arrangements as a previous step to interpreting the overall meaning of the caches. These include a graph representation of the offerings in which artefacts correspond to vertices and edges model their spatial adjacency. The specific types of graph used in this thesis are the so-called Relative Neighbourhood Graph, Gabriel Graph, Beta-skeleton, and Limited Neighbourhood Graph.

Two major steps of the RN-Method are the visualisation and quantification of global and local structure, from which it is possible to identify overall similarities or differences in the  offerings layout, as well as to make comparisons accross multiple deposits.


Exploratory Spatial Analysis; topological networks; graph-based spatial analysis method