Function d3_geo_cartesian

explainshell/web/static/js/d3.v3.js:2220–2223

(spherical)

    d3_geo_centroid.point = d3_geo_centroidPoint;
  }
  function d3_geo_cartesian(spherical) {
    var λ = spherical[0], φ = spherical[1], cosφ = Math.cos(φ);
    return [ cosφ * Math.cos(λ), cosφ * Math.sin(λ), Math.sin(φ) ];
  }
  function d3_geo_cartesianDot(a, b) {
    return a[0] * b[0] + a[1] * b[1] + a[2] * b[2];
  }