I have a table called Activity, there is a coloum called Polyline.
For each polyline I want to return it's corresponding longatude and lattitude cordinates.
A polyline is a way of encoding a series of cordinates as a string. There algorithm to do this is described here:
https://developers.google.com/maps/documentation/utilities/polylinealgorithm
I have found a Python script and function which converts a polyline into a list of longatude and lattitude cordinates:
# This function is free of any dependencies.
def decode_polyline(polyline_str):
'''Pass a Google Maps encoded polyline string; returns list of lat/lon pairs'''
index, lat, lng = 0, 0, 0
coordinates = []
changes = {'latitude': 0, 'longitude': 0}
# Coordinates have variable length when encoded, so just keep
# track of whether we've hit the end of the string. In each
# while loop iteration, a single coordinate is decoded.
while index < len(polyline_str):
# Gather lat/lon changes, store them in a dictionary to apply them later
for unit in ['latitude', 'longitude']:
shift, result = 0, 0
while True:
byte = ord(polyline_str[index]) - 63
index += 1
result |= (byte & 0x1f) << shift
shift += 5
if not byte >= 0x20:
break
if (result & 1):
changes[unit] = ~(result >> 1)
else:
changes[unit] = (result >> 1)
lat += changes['latitude']
lng += changes['longitude']
coordinates.append((lat / 100000.0, lng / 100000.0))
return coordinates
Borrowed from here https://github.com/geodav-tech/decode-google-maps-polyline
Is it possible to use this Python funciton in PowerBI and pass the polyline for each Activity and return it's coordinates?
