feat: initial commit

.eslintrc

@@ -0,0 +1,13 @@
+{
+  "extends": "airbnb-base",
+  "plugins": [
+    "import"
+  ],
+  "env": {
+    "es6": true,
+    "node": true
+  },
+  "rules": {
+    "comma-dangle": ["error", "never"]
+  }
+}

.gitignore

@@ -0,0 +1,8 @@
+.DS_Store
+node_modules/
+npm-debug.log
+yarn-error.log
+
+test/data/*
+!test/data/Makefile
+!test/data/data.md5sum

.travis.yml

@@ -0,0 +1,28 @@
+language: node_js
+dist: trusty
+sudo: required
+
+branches:
+  except:
+    - /^v[0-9]/
+
+node_js:
+  - 4
+
+addons:
+  apt:
+    sources:
+      - ubuntu-toolchain-r-test
+    packages:
+      - g++-4.8
+
+cache:
+  yarn: true
+  directories:
+    - node_modules
+
+install:
+  - yarn
+
+script:
+  - make test

API.md

@@ -0,0 +1,27 @@
+<!-- Generated by documentation.js. Update this documentation by updating the source code. -->
+
+### Table of Contents
+
+-   [isochrone](#isochrone)
+
+## isochrone
+
+Build isochrone using start point and options
+
+**Parameters**
+
+-   `startPoint` **[Array](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array)&lt;float>** start point [lng, lat]
+-   `options` **[Object](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object)** object
+    -   `options.osrm` **[Object](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object)** [osrm](https://github.com/Project-OSRM/osrm-backend) instance
+    -   `options.radius` **[number](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Number)** distance to draw the buffer as in
+        [@turf/buffer](https://github.com/Turfjs/turf/tree/master/packages/turf-buffer)
+    -   `options.cellSize` **[number](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Number)** the distance across each cell as in
+        [@turf/point-grid](https://github.com/Turfjs/turf/tree/master/packages/turf-point-grid)
+    -   `options.intervals` **[Array](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array)&lt;[number](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Number)>** intervals for isochrones in minutes
+    -   `options.concavity` **[number](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Number)** relative measure of concavity as in
+        [concaveman](https://github.com/mapbox/concaveman) (optional, default `2`)
+    -   `options.lengthThreshold` **[number](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Number)** length threshold as in
+        [concaveman](https://github.com/mapbox/concaveman) (optional, default `0`)
+    -   `options.units` **[string](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/String)** any of the options supported by turf units (optional, default `'kilometers'`)
+
+Returns **[Promise](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Promise)** promise with GeoJSON when resolved

Makefile

@@ -0,0 +1,13 @@
+all:
+	yarn
+
+clean:
+	rm -rf node_modules
+
+shm:
+	$(MAKE) all -i -C ./test/data
+
+test: shm
+	yarn test
+
+.PHONY: test clean shm

README.md

@@ -0,0 +1,40 @@
+# Isochrone
+
+[![npm version](https://img.shields.io/npm/v/isochrone.svg)](https://www.npmjs.com/package/isochrone)
+[![Build Status](https://travis-ci.org/stepankuzmin/node-isochrone.svg?branch=master)](https://travis-ci.org/stepankuzmin/node-isochrone)
+[![npm downloads](https://img.shields.io/npm/dt/isochrone.svg)](https://www.npmjs.com/package/galton)
+
+Isochrone maps are commonly used to depict areas of equal travel time.
+Build isochrones using [OSRM](http://project-osrm.org/), [Turf](http://turfjs.org/) and [concaveman](https://github.com/mapbox/concaveman).
+
+![Screenshot](https://raw.githubusercontent.com/stepankuzmin/galton/master/example.png)
+
+## Installation
+
+```
+npm install -g isochrone
+```
+
+## Usage
+
+```js
+const OSRM = require('osrm');
+const isochrone = require('isochrone');
+
+const osrm = new OSRM({ path: './monaco.osrm' });
+const startPoint = [7.41337, 43.72956];
+
+const options = {
+  osrm,
+  radius: 2,
+  cellSize: 0.1,
+  intervals: [5, 10, 15],
+};
+
+isochrone(startPoint, options)
+  .then((geojson) => {
+    console.log(JSON.stringify(geojson));
+  });
+```
+
+See [API](https://github.com/stepankuzmin/node-isochrone/blob/master/API.md) for more info.

index.js

@@ -0,0 +1,105 @@
+const buffer = require('@turf/buffer');
+const concaveman = require('concaveman');
+const pointGrid = require('@turf/point-grid');
+const rewind = require('geojson-rewind');
+
+const makeGrid = (startPoint, options) => {
+  const point = {
+    type: 'Feature',
+    geometry: {
+      type: 'Point',
+      coordinates: startPoint
+    }
+  };
+
+  const buffered = buffer(point, options.radius, options.unit);
+  const grid = pointGrid(buffered, options.cellSize, options.units);
+
+  return grid.features.map(feature => feature.geometry.coordinates);
+};
+
+const groupByInterval = (destinations, intervals, travelTime) => {
+  const intervalGroups = intervals.reduce((acc, interval) =>
+    Object.assign({}, acc, { [interval]: [] })
+  , {});
+
+  const pointsByInterval = travelTime.reduce((acc, time, index) => {
+    const timem = Math.round(time / 60);
+    const ceil = intervals.find(interval => timem <= interval);
+    if (ceil) {
+      acc[ceil].push(destinations[index].location);
+    }
+    return acc;
+  }, intervalGroups);
+
+  return pointsByInterval;
+};
+
+const makePolygon = (points, interval, options) => {
+  const concave = concaveman(points, options.concavity, options.lengthThreshold);
+
+  return {
+    type: 'Feature',
+    geometry: {
+      type: 'Polygon',
+      coordinates: [concave]
+    },
+    properties: {
+      time: parseFloat(interval)
+    }
+  };
+};
+
+const makePolygons = (pointsByInterval, options) =>
+  Object.keys(pointsByInterval).reduce((acc, interval) => {
+    const points = pointsByInterval[interval];
+    if (points.length >= 3) {
+      acc.push(makePolygon(points, interval, options));
+    }
+    return acc;
+  }, []);
+
+/**
+ * Build isochrone using start point and options
+ *
+ * @name isochrone
+ * @param {Array.<float>} startPoint start point [lng, lat]
+ * @param {Object} options object
+ * @param {Object} options.osrm - [OSRM](https://github.com/Project-OSRM/osrm-backend) instance
+ * @param {number} options.radius - distance to draw the buffer as in
+ * [@turf/buffer](https://github.com/Turfjs/turf/tree/master/packages/turf-buffer)
+ * @param {number} options.cellSize - the distance across each cell as in
+ * [@turf/point-grid](https://github.com/Turfjs/turf/tree/master/packages/turf-point-grid)
+ * @param {Array.<number>} options.intervals - intervals for isochrones in minutes
+ * @param {number} [options.concavity=2] - relative measure of concavity as in
+ * [concaveman](https://github.com/mapbox/concaveman)
+ * @param {number} [options.lengthThreshold=0] - length threshold as in
+ * [concaveman](https://github.com/mapbox/concaveman)
+ * @param {string} [options.units='kilometers'] - any of the options supported by turf units
+ * @returns {Promise} GeoJSON FeatureCollection of Polygons when resolved
+ */
+const isochrone = (startPoint, options) => {
+  const endPoints = makeGrid(startPoint, options);
+  const coordinates = [startPoint].concat(endPoints);
+
+  return new Promise((resolve, reject) => {
+    options.osrm.table({ sources: [0], coordinates }, (error, table) => {
+      if (error) {
+        reject(error);
+      }
+
+      try {
+        const travelTime = table.durations[0] || [];
+        const pointsByInterval = groupByInterval(table.destinations, options.intervals, travelTime);
+
+        const features = makePolygons(pointsByInterval, options);
+        const featureCollection = rewind({ type: 'FeatureCollection', features });
+        resolve(featureCollection);
+      } catch (e) {
+        reject(e);
+      }
+    });
+  });
+};
+
+module.exports = isochrone;

package.json

@@ -0,0 +1,50 @@
+{
+  "name": "isochrone",
+  "version": "5.7.0",
+  "description": "",
+  "author": "Stepan Kuzmin <to.stepan.kuzmin@gmail.com> (stepankuzmin.ru)",
+  "license": "MIT",
+  "main": "dist/bundle.js",
+  "jsnext:main": "src/server.js",
+  "scripts": {
+    "commit": "git-cz",
+    "release": "standard-version",
+    "docs": "documentation build index.js --format md --output API.md",
+    "lint": "eslint .",
+    "test": "node test/index.js"
+  },
+  "config": {
+    "commitizen": {
+      "path": "./node_modules/cz-conventional-changelog"
+    }
+  },
+  "engine-strict": true,
+  "engines": {
+    "node": "4"
+  },
+  "repository": {
+    "type": "git",
+    "url": "git://github.com/stepankuzmin/node-isochrone.git"
+  },
+  "dependencies": {
+    "@turf/buffer": "4.3.1",
+    "@turf/point-grid": "4.3.0",
+    "concaveman": "1.1.1",
+    "geojson-rewind": "0.2.0"
+  },
+  "peerDependencies": {
+    "osrm": "5.7.0"
+  },
+  "devDependencies": {
+    "@mapbox/geojsonhint": "2.0.1",
+    "commitizen": "2.9.6",
+    "cz-conventional-changelog": "2.0.0",
+    "documentation": "4.0.0-rc.1",
+    "osrm": "5.7.0",
+    "eslint": "3.19.0",
+    "eslint-config-airbnb-base": "11.1.3",
+    "eslint-plugin-import": "2.2.0",
+    "standard-version": "4.0.0",
+    "tape": "4.6.3"
+  }
+}

test/data/Makefile

@@ -0,0 +1,20 @@
+DATA_NAME:=monaco
+DATA_URL:=https://s3.amazonaws.com/mapbox/osrm/testing/$(DATA_NAME).osm.pbf
+DATA_POLY_URL:=https://s3.amazonaws.com/mapbox/osrm/testing/$(DATA_NAME).poly
+OSRM_BUILD_DIR=../../node_modules/osrm/lib/binding
+PROFILE_ROOT:=../../node_modules/osrm/profiles
+OSRM_EXTRACT:=$(OSRM_BUILD_DIR)/osrm-extract
+OSRM_CONTRACT:=$(OSRM_BUILD_DIR)/osrm-contract
+PROFILE:=$(PROFILE_ROOT)/car.lua
+
+all:
+	wget $(DATA_URL) -O $(DATA_NAME).osm.pbf
+	@echo "Running osrm-extract..."
+	$(OSRM_EXTRACT) -p $(PROFILE) $(DATA_NAME).osm.pbf
+	@echo "Running osrm-contract..."
+	$(OSRM_CONTRACT) $(DATA_NAME).osrm
+
+clean:
+	-rm -r $(DATA_NAME).*
+
+.PHONY: clean all

test/data/data.md5sum

@@ -0,0 +1,2 @@
+2b8dd9343d5e615afc9c67bcc7028a63  monaco.osm.pbf
+b0788991ab3791d53c1c20b6281f81ad  monaco.poly

test/index.js

@@ -0,0 +1,39 @@
+const path = require('path');
+const test = require('tape');
+const OSRM = require('osrm');
+const geojsonhint = require('@mapbox/geojsonhint');
+const isochrone = require('../index');
+
+const points = [[7.41337, 43.72956],
+                [7.41546, 43.73077],
+                [7.41862, 43.73216]];
+
+const osrmPath = path.join(__dirname, './data/monaco.osrm');
+const osrm = new OSRM({ path: osrmPath });
+
+const options = {
+  osrm,
+  radius: 2,
+  cellSize: 0.1,
+  concavity: 2,
+  intervals: [5, 10, 15],
+  lengthThreshold: 0,
+  units: 'kilometers'
+};
+
+test('isochrone', (t) => {
+  t.plan(3);
+  points.forEach(point =>
+    isochrone(point, options)
+      .then((geojson) => {
+        const errors = geojsonhint.hint(geojson);
+        if (errors.length > 0) {
+          errors.forEach(error => t.comment(error.message));
+          t.fail('Invalid GeoJSON');
+        } else {
+          t.pass('Valid GeoJSON');
+        }
+      })
+      .catch(error => t.error(error, 'No error'))
+  );
+});