Plotting Polygons with Folium and Pyproj

Question

I'm trying to plot the boundaries of the localities of Brussels. The system of coordinates of my json file has to be converted to a longlat system to display the Polygons on Folium maps. The issue I get is that my coordinates are projected into the Pacific ocean. I guess it is probably due to the fact that the parameters I set are not the good ones. Please find below my code:

import json
import pyproj
import folium

# Load JSON file
with open("districts.json", "r") as f:
    data = json.load(f)

# Create a transformation object
in_proj = pyproj.Proj(proj='utm',zone=31,datum='WGS84')
out_proj = pyproj.Proj(proj='longlat',datum='WGS84')

# Transform the coordinates
features = data["features"]
for feature in features:
    coords = feature["geometry"]["coordinates"][0]
    coords = [pyproj.transform(in_proj, out_proj, coord[0], coord[1]) for coord in coords]
    feature["geometry"]["coordinates"] = [coords]

# Plot the polyggon on a map
m = folium.Map()
folium.GeoJson(data).add_to(m)
m

This corresponds to how my json file is structured:

{"type":"FeatureCollection","features":[{"geometry":{"type":"Polygon","coordinates":[[[152914.748398394,173305.19242333],[152947.4133984,173326.530423339],...,[152961.983398418,173225.325423267],[152914.748398394,173305.19242333]]]},...

(https://i.stack.imgur.com/SuU4Q.png) (https://i.stack.imgur.com/oIKJN.png)

Does anyone has an idea how to solve this? How could I find the right parameters?

I tried different zones but I would rather know of to find the right zone number and understand how it works.

Plotting Polygons with Folium and Pyproj

0 Answers0