Reference Work Entry

Encyclopedia of GIS

pp 849-851

Patterns, Complex

  • Sanjay ChawlaAffiliated withSchool of Information Technologies, The University of Sydney


Correlated; Negatively-correlated; Spatial association; Co-location; Frequent itemset mining


Complex spatial relationships capture self, positive, negative and mixed relationships between spatial entities. These relationships abstract the commonly occurring relationships in ecology, cosmology and other disciplines where spatial referencing plays an important role. Table 1 enumerates the different types of complex relationships using the example of elliptical and spiral galaxy types from the field of cosmology. More formally, the definition of complex relationships is predicated on the concept of colocation.

Definitions 1(Co-location) Two spatial objects are said to co-locate if the Euclidean distance between the objects is less than or equal to the user‐specified neighborhood distance d.

Definitions 2(Positive) A positive relationship in spatial data is a set of features that co-locate at a ratio greater than some predefined threshold. In spati ...

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