Sha256: 5ce0d82c29c291645c0cb58fe69e9bfeb6b823ef531757dec6e7031f92158296
Contents?: true
Size: 1.81 KB
Versions: 6
Compression:
Stored size: 1.81 KB
Contents
// TODO clip input coordinates on opposite hemisphere
d3.geo.azimuthal = function() {
var mode = "orthographic", // or stereographic
origin,
scale = 200,
translate = [480, 250],
x0,
y0,
cy0,
sy0;
function azimuthal(coordinates) {
var x1 = coordinates[0] * d3_radians - x0,
y1 = coordinates[1] * d3_radians,
cx1 = Math.cos(x1),
sx1 = Math.sin(x1),
cy1 = Math.cos(y1),
sy1 = Math.sin(y1),
k = mode === "stereographic" ? 1 / (1 + sy0 * sy1 + cy0 * cy1 * cx1) : 1,
x = k * cy1 * sx1,
y = k * (sy0 * cy1 * cx1 - cy0 * sy1);
return [
scale * x + translate[0],
scale * y + translate[1]
];
}
azimuthal.invert = function(coordinates) {
var x = (coordinates[0] - translate[0]) / scale,
y = (coordinates[1] - translate[1]) / scale,
p = Math.sqrt(x * x + y * y),
c = mode === "stereographic" ? 2 * Math.atan(p) : Math.asin(p),
sc = Math.sin(c),
cc = Math.cos(c);
return [
(x0 + Math.atan2(x * sc, p * cy0 * cc + y * sy0 * sc)) / d3_radians,
Math.asin(cc * sy0 - (y * sc * cy0) / p) / d3_radians
];
};
azimuthal.mode = function(x) {
if (!arguments.length) return mode;
mode = x + "";
return azimuthal;
};
azimuthal.origin = function(x) {
if (!arguments.length) return origin;
origin = x;
x0 = origin[0] * d3_radians;
y0 = origin[1] * d3_radians;
cy0 = Math.cos(y0);
sy0 = Math.sin(y0);
return azimuthal;
};
azimuthal.scale = function(x) {
if (!arguments.length) return scale;
scale = +x;
return azimuthal;
};
azimuthal.translate = function(x) {
if (!arguments.length) return translate;
translate = [+x[0], +x[1]];
return azimuthal;
};
return azimuthal.origin([0, 0]);
};
Version data entries
6 entries across 6 versions & 1 rubygems