def get_centroids(geojson):
    """Get census tract centroids.

    :param geojson: a GeoJSON file with census tract location data
    :returns: a dictionary with tract names mapped to coordinate tuples"""
    tract_centroids = {}

    for t in geojson['features']:
        lat = t['properties']['intptlat10']
        lon = t['properties']['intptlon10']
        name = t['properties']['name10']
        tract_centroids[name] = (float(lat), float(lon))

    return tract_centroids