Sha256: 33fb3c73793012400efbbde2d5355994d9d4ffb45c71dc4591bdf254ebec7cfc
Contents?: true
Size: 1.13 KB
Versions: 4
Compression:
Stored size: 1.13 KB
Contents
import "../core/noop";
import "../math/trigonometry";
import "geo";
import "stream";
d3.geo.length = function(object) {
d3_geo_lengthSum = 0;
d3.geo.stream(object, d3_geo_length);
return d3_geo_lengthSum;
};
var d3_geo_lengthSum;
var d3_geo_length = {
sphere: d3_noop,
point: d3_noop,
lineStart: d3_geo_lengthLineStart,
lineEnd: d3_noop,
polygonStart: d3_noop,
polygonEnd: d3_noop
};
function d3_geo_lengthLineStart() {
var λ0, sinφ0, cosφ0;
d3_geo_length.point = function(λ, φ) {
λ0 = λ * d3_radians, sinφ0 = Math.sin(φ *= d3_radians), cosφ0 = Math.cos(φ);
d3_geo_length.point = nextPoint;
};
d3_geo_length.lineEnd = function() {
d3_geo_length.point = d3_geo_length.lineEnd = d3_noop;
};
function nextPoint(λ, φ) {
var sinφ = Math.sin(φ *= d3_radians),
cosφ = Math.cos(φ),
t = Math.abs((λ *= d3_radians) - λ0),
cosΔλ = Math.cos(t);
d3_geo_lengthSum += Math.atan2(Math.sqrt((t = cosφ * Math.sin(t)) * t + (t = cosφ0 * sinφ - sinφ0 * cosφ * cosΔλ) * t), sinφ0 * sinφ + cosφ0 * cosφ * cosΔλ);
λ0 = λ, sinφ0 = sinφ, cosφ0 = cosφ;
}
}
Version data entries
4 entries across 4 versions & 2 rubygems