geojson-python-utils
JavaScript Version: geojson-js-utils
This project is inspired by geojson-js-utils. Geojson becomes more popular than before. These algorithms also are what I want to learn about, which may give you some inspiration.
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Usage
Copy geojson_utils.py into your working directory, and import the modules into your py file.
from geojson_utils import linestrings_intersect
or install
pip install geojson_utils
Example
Linestrings Intersection
To valid whether linestrings from geojson are intersected with each other.
from geojson_utils import linestrings_intersect
diagonal_up_str = '{ "type": "LineString","coordinates": [[0, 0], [10, 10]]}'
diagonal_down_str = '{ "type": "LineString","coordinates": [[10, 0], [0, 10]]}'
far_away_str = '{ "type": "LineString","coordinates": [[100, 100], [110, 110]]}'
diagonal_up = json.loads(diagonal_up_str)
diagonal_down = json.loads(diagonal_down_str)
far_away = json.loads(far_away_str)
print linestrings_intersect(diagonal_up, diagonal_down)
#[{'type': 'Point', 'coordinates': [0, 0]}]
print linestrings_intersect(diagonal_up, far_away)
#[]
Point in Polygon
To valid whether the point is located in a polygon
from geojson_utils import point_in_polygon
in_str = '{"type": "Point", "coordinates": [5, 5]}'
out_str = '{"type": "Point", "coordinates": [15, 15]}'
box_str = '{"type": "Polygon","coordinates": [[ [0, 0], [10, 0], [10, 10], [0, 10] ]]}'
in_box = json.loads(in_str)
out_box = json.loads(out_str)
box = json.loads(box_str)
print point_in_polygon(in_box, box)
#True
point_in_polygon(out_box, box)
#False
Point in Multipolygon
To valid whether the point is located in a mulitpolygon (donut polygon is not supported)
from geojson_utils import point_in_multipolygon
point_str = '{"type": "Point", "coordinates": [0.5, 0.5]}'
single_point_str = '{"type": "Point", "coordinates": [-1, -1]}'
multipoly_str = '{"type":"MultiPolygon","coordinates":[[[[0,0],[0,10],[10,10],[10,0],[0,0]]],[[[10,10],[10,20],[20,20],[20,10],[10,10]]]]}'
point = json.loads(point_str)
single_point = json.loads(single_point_str)
multipoly = json.loads(multipoly_str)
print point_in_multipolygon(point, multipoly)
#True
print point_in_multipolygon(single_point, multipoly)
#False
Draw Circle
To get a circle shape polygon based on centerPoint and radius
from geojson_utils import draw_circle
pt_center = json.loads('{"type": "Point", "coordinates": [0, 0]}')
print len(draw_circle(10, pt_center)['coordinates'][0])
#15
print len(draw_circle(10, pt_center, 50)['coordinates'][0])
#50
Rectangle Centroid
To get the centroid of the rectangle
from geojson_utils import centroid
box_str = '{"type": "Polygon","coordinates": [[[0, 0],[10, 0],[10, 10],[0, 10]]]}'
box = json.loads(box_str)
centroid = rectangle_centroid(box)
print centroid['coordinates']
#[5, 5]
Distance between Two Points
To calculate the distance between two point on the sphere like google map (reference http://www.movable-type.co.uk/scripts/latlong.html)
from geojson_utils import point_distance
fairyland_str = '{"type": "Point", "coordinates": [-122.260000705719, 37.80919060818706]}'
navalbase_str = '{"type": "Point", "coordinates": [-122.32083320617676, 37.78774223089045]}'
fairyland = json.loads(fairyland_str)
navalbase = json.loads(navalbase_str)
print math.floor(point_distance(fairyland, navalbase))
# 5852
Geometry within Radius
To valid whether point or linestring or polygon is inside a radius around a center
from geojson_utils import geometry_within_radius
center_point_str = '{"type": "Point", "coordinates": [-122.260000705719, 37.80919060818706]}'
check_point_str = '{"type": "Point", "coordinates": [-122.32083320617676, 37.78774223089045]}'
center_point = json.loads(center_point_str)
check_point = json.loads(check_point_str)
print geometry_within_radius(check_point, center_point, 5853)
#True
Area
To calculate the area of polygon
from geojson_utils import area
box_str = '{"type": "Polygon","coordinates": [[ [0, 0], [10, 0], [10, 10], [0, 10] ]]}'
box = json.loads(box_str)
print area(box)
#100
Centroid
To get the centroid of polygon adapted from http://paulbourke.net/geometry/polyarea/javascript.txt
from geojson_utils import centroid
box_str = '{"type": "Polygon","coordinates": [[ [0, 0], [10, 0], [10, 10], [0, 10] ]]}'
box = json.loads(box_str)
print centroid(box)
#{"type": "Point", "coordinates": [5, 5]})
Destination point
To calculate a destination Point base on a base point and a distance
from geojson_utils import destination_point
startpoint_str = '{"type": "Point", "coordinates": [-122.260000705719, 37.80919060818706]}'
startpoint = json.loads(startpoint_str)
print destination_point(startpoint, 180, 2000)
#{'type': 'Point', 'coordinates': [-122.26000070571902, 19.822758489812447]}
Merge Featurecollection geojson
To merge features into one featurecollection
from geojson_utils import merge_featurecollection
with open('tests/first.json','r') as fp:
first = json.load(fp)
with open('tests/second.json','r') as fp:
second = json.load(fp)
with open('tests/result.json','r') as fp:
result = json.load(fp)
merge_featurecollection(first,second)
Simplify other point
Simplify the point featurecollection of poi with another point features accoording by distance.
Attention: point featurecollection only
Conversion between wgs84, gcj02, bd09
Conversion between wgs84, gcj02 and bd09
Parameter One: geojson geometry
Parameter Two:
- wgs2gcj coordinates conversion from wgs84 to gcj02
- gcj2wgs coordinates conversion from gcj02 to wgs84
- wgs2bd coordinates conversion from wgs84 to bd09
- bd2wgs coordinates conversion from bd09 to wgs84
- gcj2bd coordinates conversion from gcj02 to bd09
- bd2gcj coordinates conversion from bd09 to gcj02
from geojson_utils import convertor
with open('tests/province_wgs.geojson', encoding='utf-8') as fp:
geojson = json.load(fp)
features = geojson['features']
for feature in features:
origin = feature['geometry']['coordinates'][0][0][0]
result = convertor(feature['geometry'])
TODO
Development
On the develop branch