99
AN ALGORITHM ABOUT ASSOCIATION RULE MINING BASED ON SPATIAL
AUTOCORRELATION
Jiangping Chen a,b
a School of remote sensing Information Engineering Wuhan University, Wuhan Hubei, PR China 430079
chenjp_lisa@l 63.com, ch_lisa@hotmail.com
b Department of Geography, University of Cambridge,Downing Place, Cambridge, UK, CB2 3EN
jc564@cam.ac.uk
KEY WORDS: Geographical information science, Statistical analysis, Data mining, Geography, Spatial association rule, spatial
auto-correlation
ABSTRACT:
Most spatial data in GIS are not independent, they have high autocorrelation. For example, temperatures of nearby locations are often
related. Most of the spatial association rule mining algorithms derived from the attribute association rule mining algorithms which assume
that spatial data is independent. In these situations, the rules or knowledge derived from spatial mining will be wrong. It is, therefore,
important that mining spatial association rules take into consideration spatial autocorrelation. At present, spatial statistics are the most
common method to research spatial autocorrelation. In spatial statistics, classic statistics are extended by taking into account spatial
autocorrelation. Spatial Autoregressive Model, SAR, is one of the methods; the adjacency matrix is used to describe the interaction of
neighbouring fields which can simulate the effect of dependence between variables. The disadvantage of spatial statistics is that the
calculation consuming is high so it cannot be widely applied in spatial data mining.
This paper puts forward a new method of mining spatial association rules based on taking account of the spatial autocorrelation with
an cell structure theory. It defines spatial data with an algebra data structure then the autocorrelation of the spatial data can be calculated
in algebra. According to J. Corbett’s cell structure theory (1985), spatial graph is a subset of point, line, face, and body. The algebra
structure of point, line, face and body can be used to express spatial data. In spatial data mining, we mine rules in the spatial database.
In this paper the first step is to design a structure about point, line, face and body to express the spatial data and then store it in the
spatial database. The second step is to build the measurement model of spatial autocorrelation based on the algebra structure of spatial
data. The third step to mine the association rules based on the spatial autocorrelation model. Taking account of spatial autocorrelation is a
significance research field for mining spatial association rules. We can get the spatial frequency items from the autocorrelation of the
spatial data. This replaces the repeated scanning of the database by the measure of the spatial autocorrelation.
computer cartography, environmental assessment and planning.
The collected data far exceeds people's ability to analyze it. Thus,
new and efficient methods are needed to discover knowledge
from large spatial databases. Attribute data mining methods were
extended to applying in spatial data mining.One of the big
INTRODUCTION
Spatial data mining, i.e, mining knowledge from large amounts of
spatial data, is a demanding field since huge amounts of spatial
data have been collected in various applications, ranging from
remote sensing to geographical information systems (GIS),