Posts about GIS

In this post we will use the ogr2ogr command line tool from GDAL to convert a shapefile of NYC zip code boundary data to GeoJSON format, as well as convert the projected coordinates to latitude and longitude, in one line of code.

A Voronoi diagram divides up a space into regions of influence based on a set of points. In this post we will generate a Voronoi diagram from a map of NYC subway station locations, which can be used to find the closest subway station to any location.

Determining if a point lies in a polygon is a pretty common task in computational geometry. In this post we will use it to answer questions like 'which NYC neighborhood is this apartment building in?' using GeoDjango and data from NYC Open Data.