IDEAS home Printed from
MyIDEAS: Log in (now much improved!) to save this article

An adjacency constraint in agglomerative hierarchical classifications of geographic data

Listed author(s):
  • C R Margules
  • D P Faith
  • L Belbin
Registered author(s):

    A numerical method for classifying geographic data is presented which incorporates geographic location as an external constraint. The method was implemented by making minimal changes to an existing agglomerative hierarchical algorithm. This was seen as the simplest solution, both computationally and operationally. Given a matrix of similarities or distances calculated from the usual intrinsic variables, the classification proceeds normally with the constraint that only adjacent objects are allowed to form groups. The method has been implemented previously, but here the examination of it is extended to cover the effects of a range of different fusion strategies, and to consider chances in within-group heterogeneity as a result of imposing an adjacency constraint. Three other matters arising are discussed: the presence of regional as opposed to global outliers of a classification; the occurrence of reversals in similarity values; and a measure of the stress imposed on a classification with an adjacency constraint. The method is seen as suggesting a possible general solution to the problem of constraints in numerical classification. Some examples of other constraints and the appropriate fusion strategies are given.

    If you experience problems downloading a file, check if you have the proper application to view it first. In case of further problems read the IDEAS help page. Note that these files are not on the IDEAS site. Please be patient as the files may be large.

    File URL:
    File Function: abstract
    Download Restriction: Fulltext access restricted to subscribers, see for details

    File URL:
    File Function: main text
    Download Restriction: Fulltext access restricted to subscribers, see for details

    As the access to this document is restricted, you may want to look for a different version under "Related research" (further below) or search for a different version of it.

    Article provided by Pion Ltd, London in its journal Environment and Planning A.

    Volume (Year): 17 (1985)
    Issue (Month): 3 (March)
    Pages: 397-412

    in new window

    Handle: RePEc:pio:envira:v:17:y:1985:i:3:p:397-412
    Contact details of provider: Web page:

    No references listed on IDEAS
    You can help add them by filling out this form.

    This item is not listed on Wikipedia, on a reading list or among the top items on IDEAS.

    When requesting a correction, please mention this item's handle: RePEc:pio:envira:v:17:y:1985:i:3:p:397-412. See general information about how to correct material in RePEc.

    For technical questions regarding this item, or to correct its authors, title, abstract, bibliographic or download information, contact: (Neil Hammond)

    If you have authored this item and are not yet registered with RePEc, we encourage you to do it here. This allows to link your profile to this item. It also allows you to accept potential citations to this item that we are uncertain about.

    If references are entirely missing, you can add them using this form.

    If the full references list an item that is present in RePEc, but the system did not link to it, you can help with this form.

    If you know of missing items citing this one, you can help us creating those links by adding the relevant references in the same way as above, for each refering item. If you are a registered author of this item, you may also want to check the "citations" tab in your profile, as there may be some citations waiting for confirmation.

    Please note that corrections may take a couple of weeks to filter through the various RePEc services.

    This information is provided to you by IDEAS at the Research Division of the Federal Reserve Bank of St. Louis using RePEc data.