@turf/concave - npm Package Compare versions

Comparing version 4.6.0 to 4.7.0

index.d.ts

 /// <reference types="geojson" />
 
+import {Units} from '@turf/helpers'
+
 type Points = GeoJSON.FeatureCollection<GeoJSON.Point>;
-type Polygon = GeoJSON.Feature<GeoJSON.Polygon>;
+type Polygon = GeoJSON.Feature<GeoJSON.Polygon | GeoJSON.MultiPolygon>;
 
@@ -9,4 +11,4 @@ /**
  */
-declare function concave(points: Points, maxEdge: number, units: string): Polygon;
+declare function concave(points: Points, maxEdge: number, units?: Units): Polygon;
 declare namespace concave { }
 export = concave;

index.js

@@ -1,18 +0,18 @@
-// 1. run tin on points
-// 2. calculate lenth of all edges and area of all triangles
-// 3. remove triangles that fail the max length test
-// 4. buffer the results slightly
-// 5. merge the results
 var tin = require('@turf/tin');
-var union = require('@turf/union');
+var helpers = require('@turf/helpers');
 var distance = require('@turf/distance');
+var dissolve = require('geojson-dissolve');
+var featureEach = require('@turf/meta').featureEach;
+var feature = helpers.feature;
+var featureCollection = helpers.featureCollection;
 
 /**
- * Takes a set of {@link Point|points} and returns a concave hull polygon.
+ * Takes a set of {@link Point|points} and returns a concave hull Polygon or MultiPolygon.
  * Internally, this uses [turf-tin](https://github.com/Turfjs/turf-tin) to generate geometries.
  *
+ * @name concave
  * @param {FeatureCollection<Point>} points input points
- * @param {number} maxEdge the size of an edge necessary for part of the hull to become concave (in miles)
+ * @param {number} maxEdge the length (in 'units') of an edge necessary for part of the hull to become concave
  * @param {string} [units=kilometers] can be degrees, radians, miles, or kilometers
- * @returns {Feature<Polygon>} a concave hull
+ * @returns {Feature<(Polygon|MultiPolygon)>} a concave hull
  * @throws {Error} if maxEdge parameter is missing or unable to compute hull
@@ -34,13 +34,14 @@ * @example
  */
-function concave(points, maxEdge, units) {
-    if (typeof maxEdge !== 'number') throw new Error('maxEdge parameter is required');
+module.exports = function (points, maxEdge, units) {
+    // validation
+    if (!points) throw new Error('points is required');
+    if (maxEdge === undefined || maxEdge === null) throw new Error('maxEdge is required');
+    if (typeof maxEdge !== 'number') throw new Error('invalid maxEdge');
 
-    var tinPolys = tin(points);
-    var filteredPolys = tinPolys.features.filter(filterTriangles);
-    tinPolys.features = filteredPolys;
-    if (tinPolys.features.length < 1) {
-        throw new Error('too few polygons found to compute concave hull');
-    }
+    var cleaned = removeDuplicates(points);
 
-    function filterTriangles(triangle) {
+    var tinPolys = tin(cleaned);
+    // calculate length of all edges and area of all triangles
+    // and remove triangles that fail the max length test
+    tinPolys.features = tinPolys.features.filter(function (triangle) {
         var pt1 = triangle.geometry.coordinates[0][0];
@@ -53,20 +54,36 @@ var pt2 = triangle.geometry.coordinates[0][1];
         return (dist1 <= maxEdge && dist2 <= maxEdge && dist3 <= maxEdge);
+    });
+
+    if (tinPolys.features.length < 1) throw new Error('too few polygons found to compute concave hull');
+
+    // merge the adjacent triangles
+    var dissolved = dissolve(tinPolys.features);
+    // geojson-dissolve always returns a MultiPolygon
+    if (dissolved.coordinates.length === 1) {
+        dissolved.coordinates = dissolved.coordinates[0];
+        dissolved.type = 'Polygon';
     }
+    return feature(dissolved);
+};
 
-    return merge(tinPolys);
-}
+/**
+ * Removes duplicated points in a collection returning a new collection
+ *
+ * @private
+ * @param {FeatureCollection<Point>} points to be cleaned
+ * @returns {FeatureCollection<Point>} cleaned set of points
+ */
+function removeDuplicates(points) {
+    var cleaned = [];
+    var existing = {};
 
-function merge(polygons) {
-    var merged = JSON.parse(JSON.stringify(polygons.features[0])),
-        features = polygons.features;
-
-    for (var i = 0, len = features.length; i < len; i++) {
-        var poly = features[i];
-        if (poly.geometry) {
-            merged = union(merged, poly);
+    featureEach(points, function (pt) {
+        if (!pt.geometry) return;
+        var key = pt.geometry.coordinates.join('-');
+        if (!existing.hasOwnProperty(key)) {
+            cleaned.push(pt);
+            existing[key] = true;
         }
-    }
-    return merged;
+    });
+    return featureCollection(cleaned);
 }
-
-module.exports = concave;

package.json

 {
   "name": "@turf/concave",
-  "version": "4.6.0",
+  "version": "4.7.0",
   "description": "turf concave module",
@@ -22,5 +22,17 @@ "main": "index.js",
     "gis",
+    "concave",
     "geometry"
   ],
   "author": "Turf Authors",
+  "contributors": [
+    "Tom MacWright <@tmcw>",
+    "Lyzi Diamond <@lyzidiamond>",
+    "Denis Carriere <@DenisCarriere>",
+    "Stefano Borghi <@stebogit>",
+    "Rowan Winsemius <@rowanwins>",
+    "Daniel Pulido <@dpmcmlxxvi>",
+    "Stephen Whitmore <@noffle>",
+    "Gregor MacLennan <@gmaclennan>",
+    "Mike Bostock <@mbostock>"
+  ],
   "license": "MIT",
@@ -32,12 +44,14 @@ "bugs": {
   "devDependencies": {
-    "@turf/helpers": "^4.6.0",
     "benchmark": "^2.1.4",
-    "glob": "~4.3.5",
-    "tape": "^4.6.3"
+    "load-json-file": "^2.0.0",
+    "tape": "^4.6.3",
+    "write-json-file": "^2.1.4"
   },
   "dependencies": {
-    "@turf/distance": "^4.6.0",
-    "@turf/tin": "^4.6.0",
-    "@turf/union": "^4.6.0"
+    "@turf/distance": "4.7.0",
+    "@turf/helpers": "4.7.0",
+    "@turf/meta": "4.7.0",
+    "@turf/tin": "4.7.0",
+    "geojson-dissolve": "3.1.0"
   }
 }

README.md

@@ -5,3 +5,3 @@ # @turf/concave
 
-Takes a set of [points](http://geojson.org/geojson-spec.html#point) and returns a concave hull polygon.
+Takes a set of [points](http://geojson.org/geojson-spec.html#point) and returns a concave hull Polygon or MultiPolygon.
 Internally, this uses [turf-tin](https://github.com/Turfjs/turf-tin) to generate geometries.
@@ -12,3 +12,3 @@
 -   `points` **[FeatureCollection](http://geojson.org/geojson-spec.html#feature-collection-objects)<[Point](http://geojson.org/geojson-spec.html#point)>** input points
--   `maxEdge` **[number](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Number)** the size of an edge necessary for part of the hull to become concave (in miles)
+-   `maxEdge` **[number](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Number)** the length (in 'units') of an edge necessary for part of the hull to become concave
 -   `units` **\[[string](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/String)]** can be degrees, radians, miles, or kilometers (optional, default `kilometers`)
@@ -36,3 +36,3 @@
 
-Returns **[Feature](http://geojson.org/geojson-spec.html#feature-objects)<[Polygon](http://geojson.org/geojson-spec.html#polygon)>** a concave hull
+Returns **[Feature](http://geojson.org/geojson-spec.html#feature-objects)<([Polygon](http://geojson.org/geojson-spec.html#polygon) \| [MultiPolygon](http://geojson.org/geojson-spec.html#multipolygon))>** a concave hull
 
@@ -39,0 +39,0 @@ <!-- This file is automatically generated. Please don't edit it directly:

No alert changes

Improved metrics

Total package byte prevSize

8226

increased by20%

Lines of code

90

increased by25%

Worsened metrics

Dependency count

5

increased by66.67%

Dependency changes

• + Added@turf/helpers@4.7.0

• + Added@turf/meta@4.7.0

• + Addedgeojson-dissolve@3.1.0

• + Added@turf/distance@4.7.0(transitive)

• + Added@turf/helpers@4.7.0(transitive)

• + Added@turf/invariant@4.7.0(transitive)

• + Added@turf/meta@3.14.04.7.0(transitive)

• + Addedcommander@2.20.3(transitive)

• + Addedgeojson-dissolve@3.1.0(transitive)

• + Addedgeojson-flatten@0.2.4(transitive)

• + Addedgeojson-linestring-dissolve@0.0.1(transitive)

• + Addedget-stdin@6.0.0(transitive)

• + Addedminimist@1.2.0(transitive)

• + Addedtopojson-client@3.1.0(transitive)

• + Addedtopojson-server@3.0.1(transitive)

• - Removed@turf/union@^4.6.0

• - Removed@turf/distance@4.7.3(transitive)

• - Removed@turf/helpers@4.7.3(transitive)

• - Removed@turf/invariant@4.7.3(transitive)

• - Removed@turf/tin@4.7.3(transitive)

• - Removed@turf/union@4.7.3(transitive)

• - Removedjsts@1.3.0(transitive)

• Updated@turf/distance@4.7.0

• Updated@turf/tin@4.7.0