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MERGEPOLY: Stata module to merge adjacent polygons from a shapefile


  • Robert Picard


  • Michael Stepner


Programming Language



mergepoly inputs a shapefile in the dual Stata dataset format generated by -shp2dta- (SSC) and merges adjacent polygons by removing all shared line segments and reconnecting the remaining line segments into polygons that follow the outer borders of the original polygons. The -by()- option can be used to merge features by attribute groups. You can, for example, merge U.S. State boundaries by Census division codes and create a new shapefile that describes the division boundaries. The shapefile produced by mergepoly is in a format that can be immediately visualized using -spmap- (SSC).

Suggested Citation

  • Robert Picard & Michael Stepner, 2012. "MERGEPOLY: Stata module to merge adjacent polygons from a shapefile," Statistical Software Components S457574, Boston College Department of Economics, revised 16 Aug 2015.
  • Handle: RePEc:boc:bocode:s457574
    Note: This module should be installed from within Stata by typing "ssc install mergepoly". The module is made available under terms of the GPL v3 ( Windows users should not attempt to download these files with a web browser.

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    Citations are extracted by the CitEc Project, subscribe to its RSS feed for this item.

    Cited by:

    1. Celbis M.G. & Crombrugghe D.P.I. de, 2014. "Can internet infrastructure help reduce regional disparities? : evidence from Turkey," MERIT Working Papers 2014-078, United Nations University - Maastricht Economic and Social Research Institute on Innovation and Technology (MERIT).
    2. Mehmet Guney Celbis & Peter Nijkamp & Jacques Poot, 2015. "Infrastructure and the International Export Performance of Turkish Regions," World Scientific Book Chapters, in: Amitrajeet A Batabyal & Peter Nijkamp (ed.), THE REGION AND TRADE New Analytical Directions, chapter 11, pages 319-350, World Scientific Publishing Co. Pte. Ltd..
    3. Celbis, M.G. & Crombrugghe, D. de & Muysken, J., 2014. "Public investment and regional politics: The case of Turkey," MERIT Working Papers 2014-020, United Nations University - Maastricht Economic and Social Research Institute on Innovation and Technology (MERIT).


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