LibGEOS is a LGPL-licensed package for manipulation and analysis of planar geometric objects, based on the libraries GEOS (the engine of PostGIS) and JTS (from which GEOS is ported).

Among other things, it allows you to parse Well-known Text (WKT)

p1 = readgeom("POLYGON((0 0,1 0,1 1,0 0))")
p2 = readgeom("POLYGON((0 0,1 0,1 1,0 1,0 0))")
p3 = readgeom("POLYGON((2 0,3 0,3 1,2 1,2 0))")

Add a buffer around them

g1 = buffer(p1, 0.5)
g2 = buffer(p2, 0.5)
g3 = buffer(p3, 0.5)

and take the union of different geometries

polygon = LibGEOS.union(g1, g3)

GEOS functionality is extensive, so coverage is incomplete, but the basic functionality for working with geospatial data is already available. I'm learning as I go along, so documentation is lacking, but if you're interested, you can have a look at the examples in the examples/ folder, or the tests in test/test_geo_interface.jl and test/test_geos_operations.jl.

1. At the Julia prompt, run

julia> Pkg.add("LibGEOS")

This will install both the Julia package and GEOS shared libraries together. To just reinstall the GEOS shared libraries, run Pkg.build("LibGEOS").

2. Test that LibGEOS works by runnning

julia> Pkg.test("LibGEOS")