XYZ coordinates of the 'globe'

[ericmelse]

Dear Statalisters,

My question is not Stata related as such, but because there are packages like geocircles or geo2XY (from SSC by Robert Picard) that deal with geo-mapping, possibly someone can answer my question.

I am looking for XYZ coordinates of positions on earth, i.e. our globe.
For example, of capitals, or (sketchy) the coastline of the continents.

So, it concerns the '3D Cartesian coordinates', Earth centered, Earth fixed (ECEF) coordinates in relation to latitude and longitude (from Wikipedia):

I have searched at many sites and asked around by several organisations but so far without any result.

So, should you know where to go for such data, your help is much appreciated.

[Scott Merryman]

Taken from here: https://stackoverflow.com/questions/...an-coordinates

python:
# Converting lat/long to cartesian
import numpy as np
from sfi import Data
def get_cartesian(lat=None,lon=None):
    lat, lon = np.deg2rad(lat), np.deg2rad(lon)
    R = 6371 # radius of the earth
    x = R * np.cos(lat) * np.cos(lon)
    y = R * np.cos(lat) * np.sin(lon)
    z = R *np.sin(lat)
    return x,y,z

get_cartesian(lat = 51.5074 , lon = 0.2178)
end

//or in Stata
local latitude = 51.5074
local longitude = 0.2178

scalar r_lat = `latitude'*_pi/180
scalar r_long = `longitude'*_pi/180

scalar x =  6371 * cos(r_lat) * cos(r_long)
scalar y =  6371 * cos(r_lat) * sin(r_long)
scalar z = 6371*sin(r_lat)
disp x,y,z

If you have your data points in terms of latitude and longitude you can convert them. For example here a data set of latitude and longitude of world capitals.

[ericmelse]

Dear Scott,

Excellent advise, I have got it all working!

Many thanks.