New module @turf/line-arc

packages/turf-line-arc/LICENSE

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+The MIT License (MIT)
+
+Copyright (c) 2017 TurfJS
+
+Permission is hereby granted, free of charge, to any person obtaining a copy of
+this software and associated documentation files (the "Software"), to deal in
+the Software without restriction, including without limitation the rights to
+use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
+the Software, and to permit persons to whom the Software is furnished to do so,
+subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
+FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
+COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
+IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

packages/turf-line-arc/README.md

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+# @turf/line-arc
+
+# line-arc
+
+Creates a circular arc, of a circle of the given radius and center point, between bearing1 and bearing2;
+0 bearing is North of center point, positive clockwise.
+
+**Parameters**
+
+- `center` **[Feature](http://geojson.org/geojson-spec.html#feature-objects)<[Point](http://geojson.org/geojson-spec.html#point)>** center point
+- `radius` **[number](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Number)** radius of the circle
+- `bearing1` **[number](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Number)** angle, in decimal degrees, of the first radius of the arc
+- `bearing2` **[number](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Number)** angle, in decimal degrees, of the second radius of the arc
+- `steps` **\[[number](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Number)]** number of steps (optional, default `64`)
+- `units` **\[[string](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/String)]** miles, kilometers, degrees, or radians (optional, default `kilometers`)
+
+**Examples**
+
+```javascript
+var center = {
+ "type": "Feature",
+ "properties": {},
+ "geometry": {
+ "type": "Point",
+ "coordinates": [-75, 40]
+ }
+}
+var radius = 5;
+var bearing1 = 25;
+var bearing2 = 47;
+
+var arc = turf.lineArc(center, radius, bearing1, bearing2);
+
+//addToMap
+var addToMap = [center, arc]
+```
+
+Returns **[Feature](http://geojson.org/geojson-spec.html#feature-objects)<[LineString](http://geojson.org/geojson-spec.html#linestring)>** line arc
+
+<!-- This file is automatically generated. Please don't edit it directly:
+if you find an error, edit the source file (likely index.js), and re-run
+./scripts/generate-readmes in the turf project. -->
+
+---
+
+This module is part of the [Turfjs project](http://turfjs.org/), an open source
+module collection dedicated to geographic algorithms. It is maintained in the
+[Turfjs/turf](https:/Turfjs/turf) repository, where you can create
+PRs and issues.
+
+### Installation
+
+Install this module individually:
+
+```sh
+$ npm install @turf/line-arc
+```
+
+Or install the Turf module that includes it as a function:
+
+```sh
+$ npm install @turf/turf
+```

packages/turf-line-arc/bench.js

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+const Benchmark = require('benchmark');
+const path = require('path');
+const fs = require('fs');
+const load = require('load-json-file');
+const lineArc = require('./');
+
+const directory = path.join(__dirname, 'test', 'in') + path.sep;
+const fixtures = fs.readdirSync(directory).map(filename => {
+ return {
+ name: path.parse(filename).name,
+ geojson: load.sync(directory + filename)
+ };
+});
+
+/**
+ * Benchmark Results
+ *
+ * line-arc-full-360 x 38,879 ops/sec ±5.53% (78 runs sampled)
+ * line-arc-greater-360 x 435,501 ops/sec ±13.18% (66 runs sampled)
+ * line-arc1 x 249,765 ops/sec ±6.43% (69 runs sampled)
+ * line-arc2 x 92,964 ops/sec ±6.81% (72 runs sampled)
+ * line-arc3 x 47,342 ops/sec ±4.41% (74 runs sampled)
+ * line-arc4 x 267,112 ops/sec ±5.95% (71 runs sampled)
+ * line-arc5 x 35,259 ops/sec ±4.43% (69 runs sampled)
+ * line-arc6 x 38,674 ops/sec ±4.86% (75 runs sampled)
+ */
+const suite = new Benchmark.Suite('turf-line-arc');
+for (const {name, geojson} of fixtures) {
+ const {radius, bearing1, bearing2, steps, units} = geojson.properties;
+ suite.add(name, () => lineArc(geojson, radius, bearing1, bearing2, steps, units));
+}
+
+suite
+ .on('cycle', e => console.log(String(e.target)))
+ .on('complete', () => {})
+ .run();

packages/turf-line-arc/index.d.ts

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+/// <reference types="geojson" />
+
+import {Point, LineString, Units} from '@turf/helpers';
+
+/**
+ * http://turfjs.org/docs/#linearc
+ */
+declare function lineArc(center: Point, radius: number, bearing1: number, bearing2: number, steps?: number, units?: string): LineString;
+declare namespace lineArc { }
+export = lineArc;

packages/turf-line-arc/index.js

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+var destination = require('@turf/destination');
+var circle = require('@turf/circle');
+var lineString = require('@turf/helpers').lineString;
+
+/**
+ * Creates a circular arc, of a circle of the given radius and center point, between bearing1 and bearing2;
+ * 0 bearing is North of center point, positive clockwise.
+ *
+ * @name line-arc
+ * @param {Feature<Point>} center center point
+ * @param {number} radius radius of the circle
+ * @param {number} bearing1 angle, in decimal degrees, of the first radius of the arc
+ * @param {number} bearing2 angle, in decimal degrees, of the second radius of the arc
+ * @param {number} [steps=64] number of steps
+ * @param {string} [units="kilometers""] miles, kilometers, degrees, or radians
+ * @returns {Feature<LineString>} line arc
+ * @example
+ * var center = {
+ * "type": "Feature",
+ * "properties": {},
+ * "geometry": {
+ * "type": "Point",
+ * "coordinates": [-75, 40]
+ * }
+ * }
+ * var radius = 5;
+ * var bearing1 = 25;
+ * var bearing2 = 47;
+ *
+ * var arc = turf.lineArc(center, radius, bearing1, bearing2);
+ *
+ * //addToMap
+ * var addToMap = [center, arc]
+ */
+module.exports = function (center, radius, bearing1, bearing2, steps, units) {
+ // validation
+ if (!center) throw new Error('center is required');
+ if (bearing1 === undefined || bearing1 === null) throw new Error('bearing1 is required');
+ if (bearing2 === undefined || bearing2 === null) throw new Error('bearing2 is required');
+ if (!radius) throw new Error('radius is required');
+
+ // default params
+ steps = steps || 64;
+
+ var angle1 = convertAngleTo360(bearing1);
+ var angle2 = convertAngleTo360(bearing2);
+ var properties = center.properties;
+
+ // handle angle parameters
+ if (angle1 === angle2) {
+ return lineString(circle(center, radius, steps, units).geometry.coordinates[0], properties);
+ }
+ var arcStartDegree = angle1;
+ var arcEndDegree = (angle1 < angle2) ? angle2 : angle2 + 360;
+
+ var alfa = arcStartDegree;
+ var coordinates = [];
+ var i = 0;
+
+ while (alfa < arcEndDegree) {
+ coordinates.push(destination(center, radius, alfa, units).geometry.coordinates);
+ i++;
+ alfa = arcStartDegree + i * 360 / steps;
+ }
+ if (alfa > arcEndDegree) {
+ coordinates.push(destination(center, radius, arcEndDegree, units).geometry.coordinates);
+ }
+ return lineString(coordinates, properties);
+};
+
+
+/**
+ * Takes any angle in degrees
+ * and returns a valid angle between 0-360 degrees
+ *
+ * @private
+ * @param {number} alfa angle between -180-180 degrees
+ * @returns {number} angle between 0-360 degrees
+ */
+function convertAngleTo360(alfa) {
+ var beta = alfa % 360;
+ if (beta < 0) {
+ beta += 360;
+ }
+ return beta;
+}

packages/turf-line-arc/package.json

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+{
+ "name": "@turf/line-arc",
+ "version": "4.0.0",
+ "description": "turf line-arc module",
+ "main": "index.js",
+ "types": "index.d.ts",
+ "files": [
+ "index.js",
+ "index.d.ts"
+ ],
+ "scripts": {
+ "test": "node test.js",
+ "bench": "node bench.js"
+ },
+ "repository": {
+ "type": "git",
+ "url": "git:/Turfjs/turf.git"
+ },
+ "keywords": [
+ "turf",
+ "gif"
+ ],
+ "author": "Turf Authors",
+ "license": "MIT",
+ "bugs": {
+ "url": "https:/Turfjs/turf/issues"
+ },
+ "homepage": "https:/Turfjs/turf",
+ "devDependencies": {
+ "@turf/truncate": "^4.0.1",
+ "benchmark": "^2.1.4",
+ "load-json-file": "^2.0.0",
+ "tape": "^4.6.3",
+ "write-json-file": "^2.0.0"
+ },
+ "dependencies": {
+ "@turf/circle": "^4.0.1",
+ "@turf/destination": "^4.0.1",
+ "@turf/helpers": "^4.0.1",
+ "@turf/meta": "^4.0.1"
+ }
+}

packages/turf-line-arc/test.js

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+const test = require('tape');
+const fs = require('fs');
+const path = require('path');
+const load = require('load-json-file');
+const write = require('write-json-file');
+const truncate = require('@turf/truncate');
+const featureCollection = require('@turf/helpers').featureCollection;
+const lineArc = require('./');
+
+const directories = {
+ in: path.join(__dirname, 'test', 'in') + path.sep,
+ out: path.join(__dirname, 'test', 'out') + path.sep
+};
+
+const fixtures = fs.readdirSync(directories.in).map(filename => {
+ return {
+ filename,
+ name: path.parse(filename).name,
+ geojson: load.sync(directories.in + filename)
+ };
+});
+
+test('turf-line-arc', t => {
+ for (const {filename, name, geojson} of fixtures) {
+ const {radius, bearing1, bearing2, steps, units} = geojson.properties;
+ const arc = truncate(lineArc(geojson, radius, bearing1, bearing2, steps, units));
+ const results = featureCollection([geojson, arc]);
+
+ if (process.env.REGEN) write.sync(directories.out + filename, results);
+ t.deepEquals(results, load.sync(directories.out + filename), name);
+ }
+ t.end();
+});

packages/turf-line-arc/test/in/line-arc-full-360.geojson

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+{
+ "type": "Feature",
+ "properties": {
+ "radius": 5,
+ "bearing1": 180,
+ "bearing2": -180
+ },
+ "geometry": {
+ "type": "Point",
+ "coordinates": [
+ 11.343,
+ 44.495
+ ]
+ }
+}

packages/turf-line-arc/test/in/line-arc-greater-360.geojson

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+{
+ "type": "Feature",
+ "properties": {
+ "radius": 5,
+ "bearing1": 0,
+ "bearing2": 380
+ },
+ "geometry": {
+ "type": "Point",
+ "coordinates": [
+ 11.343,
+ 44.495
+ ]
+ }
+}

packages/turf-line-arc/test/in/line-arc1.geojson

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+{
+ "type": "Feature",
+ "properties": {
+ "radius": 5,
+ "bearing1": 20,
+ "bearing2": 60
+ },
+ "geometry": {
+ "type": "Point",
+ "coordinates": [
+ 11.343,
+ 44.495
+ ]
+ }
+}

packages/turf-line-arc/test/in/line-arc2.geojson

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+{
+ "type": "Feature",
+ "properties": {
+ "radius": 5,
+ "bearing1": 90,
+ "bearing2": -135
+ },
+ "geometry": {
+ "type": "Point",
+ "coordinates": [
+ 11.343,
+ 44.495
+ ]
+ }
+}

packages/turf-line-arc/test/in/line-arc3.geojson

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+{
+ "type": "Feature",
+ "properties": {
+ "radius": 5,
+ "bearing1": 45,
+ "bearing2": -45
+ },
+ "geometry": {
+ "type": "Point",
+ "coordinates": [
+ 11.343,
+ 44.495
+ ]
+ }
+}

packages/turf-line-arc/test/in/line-arc4.geojson

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+{
+ "type": "Feature",
+ "properties": {
+ "radius": 5,
+ "bearing1": -50,
+ "bearing2": -15
+ },
+ "geometry": {
+ "type": "Point",
+ "coordinates": [
+ 11.343,
+ 44.495
+ ]
+ }
+}