geodist 0.4

GeoDist Package

Geodist

Finds the distance between a POI (point of interest) and a geometric shape on Earth's surface

Objective

Find the distance between a point of interest and a geometric shape – polygon, circle, line string and a Point on earth’s surface using latitude and longitude associated with the geographic coordinate system

Install

pip install geodist

How Does It Work?

First, we convert an array of points (lng, lat) to a planar geometric object.

Then, we project the geometric object from the World Geodetic System (aka: WGS84) to the World Azimuthal Equidistant Projection (aka: ESRI:54032) with our POI as the center point of the projection.

The azimuthal equidistant projection is a map projection where all points on the map are at proportionally correct distances from the center.

Examples

Polygon

The distance between a polygon and a POI

>>> from geodist import GeoDist
>>> coords = [(4.3466824, 50.8584046), (4.3371552, 50.8490306), (4.3429917, 50.8336379), (4.3488282, 50.8330958),
...           (4.3658226, 50.8409013), (4.3695992, 50.8473506), (4.3679684, 50.8526612), (4.3466824, 50.8584046)]
... 
>>> lng, lat = 4.3821081, 50.8133681
>>> GeoDist(coords).distance(lng, lat)
3153.3015428957347

Circle

The distance between circles and a POI

>>> from geodist import GeoDist
>>> coords = [(-77.120923, 39.056418)]
>>> lng, lat = -77.145146, 39.047193
>>> GeoDist(coords, radius=1000).distance(lng, lat)
1334.582257003439
>>> GeoDist(coords, radius=2000).distance(lng, lat)
335.7868006642301
>>> GeoDist(coords, radius=3000).distance(lng, lat)
663.0086557682768

Another feature of GeoDist can tell if the POI is inside or outside the shape:

>>> a = GeoDist(coords, radius=1000)
>>> distance = a.distance(lng, lat)
>>> a.within
False

>>> b = GeoDist(coords, radius=3000)
>>> distance = b.distance(lng, lat)
>>> b.within
True

Linestring

The distance between a Linestring and a POI

>>> from geodist import GeoDist
>>> coords = [(-121.77919, 36.24285), (-121.77939, 36.24317), (-121.77955, 36.24336), (-121.77967, 36.24347),
          (-121.77977, 36.24358), (-121.78, 36.24378), (-121.78033, 36.24409), (-121.78052, 36.24433),
..............]
>>> lng, lat = -121.88728, 37.33901
>>> GeoDist(coords).distance(lng, lat)
39603.30198998547