GeoRefine

GeoRefine is a geospatial processing extension for OpenRefine.

GREL functions

• point: creates a point from latitude and longitude in the WGS84 coordinate reference system
• distance: computes the distance between two points in meters
• parseGeoJson: parses GeoJSON string
• parseWkt: parses WKT string
• All geometry relationship functions described here:
  • equals
  • contains
  • within
  • overlaps
  • crosses
  • touches
  • intersects
  • disjoint
  • relate

Installation

Download GeoRefine and place the unzipped folder in the extensions directory of your OpenRefine workspace.

On OS X, this will be /Applications/Google Refine.app/Contents/Resources/webapp/extensions.

Examples

Using GREL to facet places based on whether they're contained by the Barrington Atlas capgrid for Byzantium:

contains(parseGeoJson("{\"type\": \"Polygon\", \"coordinates\": [[[31.0, 40.0], [31.0, 42.0], [27.0, 42.0], [27.0, 40.0], [31.0, 40.0]]]}"),parseGeoJson(value))

Feature Wishlist

• parsing geospatial information from and to GeoJSON/WKT
• spatial operations in GREL: distance, area, contains, overlaps, touches, equals, crosses, disjoint, within
• spatial faceting on spatial operations
• spatial clustering
• simple spatial visualization

Compiling

Unlike most OpenRefine extensions, GeoRefine uses maven instead of ant, due to the need for complicated GeoTools dependencies. Run mvn compile to compile Java source to classes. If you update dependencies, run mvn dependency:copy-dependencies to install them into target. You'll then need to manually move them into module/MOD-INF/lib, taking care to remove conflicting jars already provided by OpenRefine such as openrefine-1.0.jar and json-20100208.jar. GeoRefine is expected to be built in the extensions directory of an OpenRefine source tree, with the OpenRefine system jar built in that tree with the ant jar task.