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mbostockmbostock
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Merge branch 'geo-length' into 3.1.0
2 parents 995b699 + f4a4d70 commit e8d8b13

5 files changed

Lines changed: 120 additions & 5 deletions

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‎Makefile‎

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@@ -211,6 +211,7 @@ d3.geo.js: \
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src/geo/path-centroid.js \
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src/geo/area.js \
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src/geo/centroid.js \
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src/geo/length.js \
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src/geo/projection.js \
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src/geo/rotation.js \
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src/geo/stereographic.js \

‎d3.js‎

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@@ -6564,6 +6564,35 @@ d3 = function() {
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nextPoint(λ00, φ00);
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};
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}
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d3.geo.length = function(object) {
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d3_geo_lengthSum = 0;
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d3.geo.stream(object, d3_geo_length);
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return d3_geo_lengthSum;
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};
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var d3_geo_lengthSum;
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var d3_geo_length = {
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sphere: d3_noop,
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point: d3_noop,
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lineStart: d3_geo_lengthLineStart,
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lineEnd: d3_noop,
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polygonStart: d3_noop,
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polygonEnd: d3_noop
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};
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function d3_geo_lengthLineStart() {
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var λ0, sinφ0, cosφ0;
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d3_geo_length.point = function(λ, φ) {
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λ0 = λ * d3_radians, sinφ0 = Math.sin(φ *= d3_radians), cosφ0 = Math.cos(φ);
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d3_geo_length.point = nextPoint;
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};
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d3_geo_length.lineEnd = function() {
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d3_geo_length.point = d3_geo_length.lineEnd = d3_noop;
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};
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function nextPoint(λ, φ) {
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var sinφ = Math.sin(φ *= d3_radians), cosφ = Math.cos(φ), t = Math.abs((λ *= d3_radians) - λ0), cosΔλ = Math.cos(t);
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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);
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λ0 = λ, sinφ0 = sinφ, cosφ0 = cosφ;
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}
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}
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d3.geo.projection = d3_geo_projection;
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d3.geo.projectionMutator = d3_geo_projectionMutator;
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function d3_geo_projection(project) {

‎d3.min.js‎

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‎src/geo/length.js‎

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d3.geo.length = function(object) {
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d3_geo_lengthSum = 0;
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d3.geo.stream(object, d3_geo_length);
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return d3_geo_lengthSum;
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};
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var d3_geo_lengthSum;
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var d3_geo_length = {
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sphere: d3_noop,
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point: d3_noop,
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lineStart: d3_geo_lengthLineStart,
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lineEnd: d3_noop,
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polygonStart: d3_noop,
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polygonEnd: d3_noop
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};
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function d3_geo_lengthLineStart() {
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var λ0, sinφ0, cosφ0;
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d3_geo_length.point = function(λ, φ) {
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λ0 = λ * d3_radians, sinφ0 = Math.sin(φ *= d3_radians), cosφ0 = Math.cos(φ);
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d3_geo_length.point = nextPoint;
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};
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d3_geo_length.lineEnd = function() {
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d3_geo_length.point = d3_geo_length.lineEnd = d3_noop;
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};
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function nextPoint(λ, φ) {
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var sinφ = Math.sin(φ *= d3_radians),
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cosφ = Math.cos(φ),
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t = Math.abs((λ *= d3_radians) - λ0),
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cosΔλ = Math.cos(t);
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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);
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λ0 = λ, sinφ0 = sinφ, cosφ0 = cosφ;
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}
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}

‎test/geo/length-test.js‎

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require("../env");
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var vows = require("vows"),
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assert = require("assert");
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var suite = vows.describe("d3.geo.length");
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var π = Math.PI;
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suite.addBatch({
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"length": {
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topic: function() {
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return d3.geo.length;
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},
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"the length of points are zero": function(length) {
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assert.inDelta(length({type: "Point", coordinates: [0, 0]}), 0, 1e-6);
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assert.inDelta(length({type: "MultiPoint", coordinates: [[0, 1], [2, 3]]}), 0, 1e-6);
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},
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"the length of a line string is the sum of its great arc segments": function(length) {
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assert.inDelta(length({type: "LineString", coordinates: [[-45, 0], [45, 0]]}), Math.PI / 2, 1e-6);
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assert.inDelta(length({type: "LineString", coordinates: [[-45, 0], [-30, 0], [-15, 0], [0, 0]]}), Math.PI / 4, 1e-6);
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assert.inDelta(length({type: "MultiLineString", coordinates: [[[-45, 0], [-30, 0]], [[-15, 0], [0, 0]]]}), Math.PI / 6, 1e-6);
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},
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"the length of a polygon is its perimeter": function(length) {
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assert.inDelta(length({type: "Polygon", coordinates: [[[0, 0], [3, 0], [3, 3], [0, 3], [0, 0]]]}), 0.157008, 1e-6);
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assert.inDelta(length({type: "MultiPolygon", coordinates: [[[[0, 0], [3, 0], [3, 3], [0, 3], [0, 0]]]]}), 0.157008, 1e-6);
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assert.inDelta(length({type: "MultiPolygon", coordinates: [[[[0, 0], [3, 0], [3, 3], [0, 3], [0, 0]]], [[[1, 1], [2, 1], [2, 2], [1, 2], [1, 1]]]]}), 0.209354, 1e-6);
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},
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"the length of a polygon is its perimeter, including holes": function(length) {
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assert.inDelta(length({type: "Polygon", coordinates: [[[0, 0], [3, 0], [3, 3], [0, 3], [0, 0]], [[1, 1], [2, 1], [2, 2], [1, 2], [1, 1]]]}), 0.209354, 1e-6);
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},
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"the length of a feature collection is the sum of its features": function(length) {
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assert.inDelta(length({type: "FeatureCollection", features: [
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{type: "Feature", geometry: {type: "LineString", coordinates: [[-45, 0], [0, 0]]}},
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{type: "Feature", geometry: {type: "LineString", coordinates: [[0, 0], [45, 0]]}}
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]}), Math.PI / 2, 1e-6);
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},
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"the length of a geometry collection is the sum of its geometries": function(length) {
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assert.inDelta(length({type: "GeometryCollection", geometries: [
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{type: "GeometryCollection", geometries: [{type: "LineString", coordinates: [[-45, 0], [0, 0]]}]},
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{type: "LineString", coordinates: [[0, 0], [45, 0]]}
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]}), Math.PI / 2, 1e-6);
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}
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}
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});
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suite.export(module);

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