Lets say I have 2 kind of coordinate, first called center_point
and second called test_point
. I want to know if test_point
coordinate is inside near or not to center_point
coordinate by applying radius
threshold. If I write it, its like:
center_point = [{'lat': -7.7940023, 'lng': 110.3656535}]
test_point = [{'lat': -7.79457, 'lng': 110.36563}]
radius = 5 # in kilometer
How to check if the test_point
inside or outside the radius from center_point
in Python? how I perform this kind task in Python?
Result expected will say that test_point
inside or outside the radius
from center_point
coordinate.
using a function called . within() that checks if a point is within a polygon. using a function called . contains() that checks if a polygon contains a point.
Draw a horizontal line to the right of each point and extend it to infinity. Count the number of times the line intersects with polygon edges. A point is inside the polygon if either count of intersections is odd or point lies on an edge of polygon. If none of the conditions is true, then point lies outside.
How to check if a point is inside a polygon in Python. To perform a Point in Polygon (PIP) query in Python, we can resort to the Shapely library's functions . within(), to check if a point is within a polygon, or . contains(), to check if a polygon contains a point.
The simplest way to determine if a point lies inside a triangle is to check the number of points in the convex hull of the vertices of the triangle adjoined with the point in question. If the hull has three points, the point lies in the triangle's interior; if it is four, it lies outside the triangle.
from recommendation of @user1753919 in his/her comment, I got the answer here: Haversine Formula in Python (Bearing and Distance between two GPS points)
final code:
from math import radians, cos, sin, asin, sqrt
def haversine(lon1, lat1, lon2, lat2):
"""
Calculate the great circle distance between two points
on the earth (specified in decimal degrees)
"""
# convert decimal degrees to radians
lon1, lat1, lon2, lat2 = map(radians, [lon1, lat1, lon2, lat2])
# haversine formula
dlon = lon2 - lon1
dlat = lat2 - lat1
a = sin(dlat/2)**2 + cos(lat1) * cos(lat2) * sin(dlon/2)**2
c = 2 * asin(sqrt(a))
r = 6371 # Radius of earth in kilometers. Use 3956 for miles
return c * r
center_point = [{'lat': -7.7940023, 'lng': 110.3656535}]
test_point = [{'lat': -7.79457, 'lng': 110.36563}]
lat1 = center_point[0]['lat']
lon1 = center_point[0]['lng']
lat2 = test_point[0]['lat']
lon2 = test_point[0]['lng']
radius = 1.00 # in kilometer
a = haversine(lon1, lat1, lon2, lat2)
print('Distance (km) : ', a)
if a <= radius:
print('Inside the area')
else:
print('Outside the area')
Thanks
GeoPy can handle it gracefully:
from geopy import distance
center_point = [{'lat': -7.7940023, 'lng': 110.3656535}]
test_point = [{'lat': -7.79457, 'lng': 110.36563}]
radius = 5 # in kilometer
center_point_tuple = tuple(center_point[0].values()) # (-7.7940023, 110.3656535)
test_point_tuple = tuple(test_point[0].values()) # (-7.79457, 110.36563)
dis = distance.distance(center_point_tuple, test_point_tuple).km
print("Distance: {}".format(dis)) # Distance: 0.0628380925748918
if dis <= radius:
print("{} point is inside the {} km radius from {} coordinate".format(test_point_tuple, radius, center_point_tuple))
else:
print("{} point is outside the {} km radius from {} coordinate".format(test_point_tuple, radius, center_point_tuple))
or if you need to know the great circle distance:
dis = distance.great_circle(center_point_tuple, test_point_tuple).km
print("Distance: {}".format(dis)) # Distance: 0.0631785164583489
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