3

Reading the documentation...it looks like I should have this right, but I don't.

The example is:

Point(0,0).distance(Point(1,1))

1.4142135623730951

Based on this example I wrote this block (..note: update, 'capital' starts as a shapely obj, and city_pt is a dict...full of multipoints it appears, looking like this).

[{'geometry': {'type': 'MultiPoint', 'coordinates': [(4942585.391221348, #3940520.723517349)]}, 'type': 'Feature', 'id': '17', 'properties': OrderedDict([(u'Status', u'Bad')])}]

    # capital = shapely obj
    capital_pt = capital.coords
    # city_point is a dict ... multipoints
    for city_point in filtered_all:
        city_items = shape(city_point['geometry'])
        # capital_pt = POINT (13531245.47570414 2886003.268927813) 
        # city_items[0] = POINT (4942585.391221348 3940520.723517349)

        # measure distance

        # calculate the distance between capital and cities
        distance_between_pts = capital_pt.distance(city_point)

and got this:

AttributeError: 'CoordinateSequence' object has no attribute 'distance'

trying the om_henners answer I get

AttributeError: 'dict' object has no attribute 'coords'

Just in terminal I tried this:

x = POINT (13531245.47570414 2886003.268927813).distance(POINT (4942585.391221348 3940520.723517349))

File "", line 1 x = POINT (13531245.47570414 2886003.268927813).distance(POINT (4942585.391221348 3940520.723517349)) ^ SyntaxError: invalid syntax

2

Your capital_pt is the coords attribute of the original capital shapely geometry object. In itself this is not a shapely geometry, rather a sequence of tuples of flots which are the point objects. Instead you should be using

distance_between_pts = capital.distance(city_items)

Given your case where you're trying to calculate distances for all points in a dataset opened by fiona, a quick example might help also:

import fiona
import shapely.geometry

# capital is a shapely geometry object

with fiona.open(path_to_data) as src:
    for feature in src:
        geom = shapely.geometry.shape(feature["geometry"])
        distance_between_pts = capital.distance(geom)
        print(distance_between_pts)
  • city_point is a dict. So that's basically: <class 'shapely.geometry.point.Point'> # capital <type 'dict'> # city_point – user14696 Mar 24 '15 at 5:24
  • Could this be a problem?...it appears I have MultiPoints (and capital is a Point). [{'geometry': {'type': 'MultiPoint', 'coordinates': [(4942585.391221348, 3940520.723517349)]}, 'type': 'Feature', 'id': '17', 'properties': OrderedDict([(u'Status', u'Bad')])}] – user14696 Mar 24 '15 at 5:27
  • @user14696 Updated my answer to reference city_items instead of city_point. Basically you want to use distance between two shapely geometries. And no, since there's only a single point in your MultiPoint geometry it should work fine for distance calculations. – om_henners Mar 24 '15 at 5:31
  • good to know the multipoint is okay...but still running into road blocks. AttributeError: 'dict' object has no attribute 'coords'. distance_between_pts = capital.distance(city_items.coords) gives me the ' "Multi-part geometries do not provide a coordinate sequence") NotImplementedError: Multi-part geometries do not provide a coordinate sequence'. – user14696 Mar 24 '15 at 5:34
  • It should just be between the two shapely geometries, i.e. distance_between_pts = capital.distance(city_items) where both capital and city_items are shapely geometry objects. Ignore the coords attribute :) – om_henners Mar 24 '15 at 5:39
1

POINT (13531245.47570414 2886003.268927813) is not a Shapely object but the WKT format of a Point

A point in Shapely is :

point1 =  Point(13531245.47570414,2886003.268927813)
type(point1)
<class 'shapely.geometry.point.Point'>

The WKT representation of the point is:

# WKT
print point1.wkt
POINT (13531245.47570414 2886003.268927813)
type(point1.wkt)
<type 'str'>

So, the correct formulation is Shapely_geometry.dist(Shapely_geometry) and not str.distance(str):

x = Point(13531245.47570414,2886003.268927813).distance(Point(4942585.391221348,3940520.723517349))
print x
8653154.86449

If you want to use the coordinates from the result of Fiona (without Shapely, your question How to call 'shapely' .coords on a fiona filtered list?)

import math # or numpy
def euclidean_distance( l1,l2):
    return math.sqrt((l2[0]-l1[0])**2 + (l2[1]-l1[1])**2)
 print euclidean_distance((13531245.47570414,2886003.268927813),(4942585.391221348,3940520.723517349))   
8653154.864488555

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