@turf/line-distance - npm Package Compare versions

Comparing version 3.13.0 to 3.14.0

index.d.ts

 /// <reference types="geojson" />
 
-type LineStrings = GeoJSON.FeatureCollection<GeoJSON.LineString>;
-type LineString = GeoJSON.Feature<GeoJSON.LineString>;
-type MultiLineStrings = GeoJSON.FeatureCollection<GeoJSON.MultiLineString>;
-type MultiLineString = GeoJSON.Feature<GeoJSON.MultiLineString>;
-type Polygons = GeoJSON.FeatureCollection<GeoJSON.Polygon>;
-type Polygon = GeoJSON.Feature<GeoJSON.Polygon>;
-type MultiPolygons = GeoJSON.FeatureCollection<GeoJSON.MultiPolygon>;
-type MultiPolygon = GeoJSON.Feature<GeoJSON.MultiPolygon>;
-type LineStringFeatures = LineString | LineStrings | MultiLineString | MultiLineStrings | GeoJSON.LineString | GeoJSON.MultiLineString
-type PolygonFeatures = Polygon | Polygons | MultiPolygon | MultiPolygons | GeoJSON.Polygon | GeoJSON.MultiPolygon
+type Geometry = GeoJSON.Polygon | GeoJSON.LineString | GeoJSON.MultiLineString | GeoJSON.MultiPolygon
+type Feature = GeoJSON.Feature<GeoJSON.Polygon | GeoJSON.LineString | GeoJSON.MultiLineString | GeoJSON.MultiPolygon>
+type Features = GeoJSON.FeatureCollection<GeoJSON.Polygon | GeoJSON.LineString | GeoJSON.MultiLineString | GeoJSON.MultiPolygon>
 
@@ -17,4 +10,4 @@ /**
  */
-declare function lineDistance(features: LineStringFeatures | PolygonFeatures, units?: string): number;
+declare function lineDistance(features: Geometry | Feature | Features, units?: string): number;
 declare namespace lineDistance { }
 export = lineDistance;

index.js

 var distance = require('@turf/distance');
+var featureEach = require('@turf/meta').featureEach;
+var coordReduce = require('@turf/meta').coordReduce;
+var geomEach = require('@turf/meta').geomEach;
+var flatten = require('@turf/flatten');
+var lineString = require('@turf/helpers').lineString;
 var point = require('@turf/helpers').point;
@@ -8,5 +13,5 @@
  * @name lineDistance
- * @param {Feature<(LineString|Polygon)>|FeatureCollection<(LineString|Polygon)>} line line to measure
+ * @param {Feature<(LineString|Polygon)>|FeatureCollection<(LineString|Polygon)>} geojson feature to measure
  * @param {string} [units=kilometers] can be degrees, radians, miles, or kilometers
- * @return {number} length of the input line
+ * @returns {number} length feature
  * @example
@@ -35,49 +40,72 @@ * var line = {
  */
-module.exports = function lineDistance(line, units) {
-    if (line.type === 'FeatureCollection') {
-        return line.features.reduce(function (memo, feature) {
-            return memo + lineDistance(feature, units);
-        }, 0);
-    }
+module.exports = function lineDistance(geojson, units) {
+    // Input Validation
+    if (!geojson) throw new Error('geojson is required');
+    geomEach(geojson, function (geometry) {
+        if (geometry.type === 'Point') throw new Error('geojson cannot be a Point');
+        if (geometry.type === 'MultiPoint') throw new Error('geojson cannot be a MultiPoint');
+    });
 
-    var geometry = line.type === 'Feature' ? line.geometry : line;
-    var d, i;
-
-    if (geometry.type === 'LineString') {
-        return length(geometry.coordinates, units);
-    } else if (geometry.type === 'Polygon' || geometry.type === 'MultiLineString') {
-        d = 0;
-        for (i = 0; i < geometry.coordinates.length; i++) {
-            d += length(geometry.coordinates[i], units);
-        }
-        return d;
-    } else if (geometry.type === 'MultiPolygon') {
-        d = 0;
-        for (i = 0; i < geometry.coordinates.length; i++) {
-            for (var j = 0; j < geometry.coordinates[i].length; j++) {
-                d += length(geometry.coordinates[i][j], units);
-            }
-        }
-        return d;
-    } else {
-        throw new Error('input must be a LineString, MultiLineString, ' +
-            'Polygon, or MultiPolygon Feature or Geometry (or a FeatureCollection ' +
-            'containing only those types)');
-    }
-
+    // Calculate distance from 2-vertex line segements
+    return segmentReduce(geojson, function (previousValue, segment) {
+        var coords = segment.geometry.coordinates;
+        var start = point(coords[0]);
+        var end = point(coords[1]);
+        return previousValue + distance(start, end, units);
+    }, 0);
 };
 
-function length(coords, units) {
-    var travelled = 0;
-    var prevCoords = point(coords[0]);
-    var curCoords = point(coords[0]);
-    var temp;
-    for (var i = 1; i < coords.length; i++) {
-        curCoords.geometry.coordinates = coords[i];
-        travelled += distance(prevCoords, curCoords, units);
-        temp = prevCoords;
-        prevCoords = curCoords;
-        curCoords = temp;
-    }
-    return travelled;
+/**
+ * Iterate over 2-vertex line segment in any GeoJSON object, similar to Array.forEach()
+ *
+ * @private
+ * @param {FeatureCollection|Feature<any>} geojson any GeoJSON
+ * @param {Function} callback a method that takes (currentSegment, currentIndex)
+ * @returns {void}
+ * @example
+ * var polygon = {
+ *   "type": "Feature",
+ *   "properties": {},
+ *   "geometry": {
+ *     "type": "Polygon",
+ *     "coordinates": [[[-50, 5], [-40, -10], [-50, -10], [-40, 5], [-50, 5]]]
+ *   }
+ * }
+ * turf.segmentEach(polygon, function (segment) {
+ *   //= segment
+ * });
+ */
+function segmentEach(geojson, callback) {
+    var count = 0;
+    featureEach(geojson, function (multiFeature) {
+        featureEach(flatten(multiFeature), function (feature) {
+            coordReduce(feature, function (previousCoords, currentCoords) {
+                var line = lineString([previousCoords, currentCoords], feature.properties);
+                callback(line, count);
+                count++;
+                return currentCoords;
+            });
+        });
+    });
 }
+
+/**
+ * Reduce 2-vertex line segment in any GeoJSON object, similar to Array.reduce()
+ *
+ * @private
+ * @param {FeatureCollection|Feature<any>} geojson any GeoJSON
+ * @param {Function} callback a method that takes (previousValue, currentSegment, currentIndex)
+ * @param {*} [initialValue] Value to use as the first argument to the first call of the callback.
+ * @returns {void}
+ */
+function segmentReduce(geojson, callback, initialValue) {
+    var previousValue = initialValue;
+    segmentEach(geojson, function (currentSegment, currentIndex) {
+        if (currentIndex === 0 && initialValue === undefined) {
+            previousValue = currentSegment;
+        } else {
+            previousValue = callback(previousValue, currentSegment, currentIndex);
+        }
+    });
+    return previousValue;
+}

package.json

 {
   "name": "@turf/line-distance",
-  "version": "3.13.0",
+  "version": "3.14.0",
   "description": "turf line-distance module",
@@ -34,9 +34,13 @@ "main": "index.js",
   "devDependencies": {
-    "benchmark": "^1.0.0",
-    "tape": "^3.5.0"
+    "benchmark": "^2.1.3",
+    "load-json-file": "^2.0.0",
+    "tape": "^4.6.3",
+    "write-json-file": "^2.0.0"
   },
   "dependencies": {
-    "@turf/distance": "^3.13.0",
-    "@turf/helpers": "^3.13.0"
+    "@turf/distance": "^3.14.0",
+    "@turf/flatten": "^3.14.0",
+    "@turf/helpers": "^3.13.0",
+    "@turf/meta": "^3.14.0"
   }
 }

No alert changes

Improved metrics

Total package byte prevSize

8349

increased by11.95%

Lines of code

115

increased by23.66%

Worsened metrics

Dependency count

4

increased by100%

Dev dependency count

4

increased by100%

Dependency changes

• + Added@turf/flatten@^3.14.0

• + Added@turf/meta@^3.14.0

• + Added@turf/flatten@3.14.2(transitive)

• + Added@turf/meta@3.14.0(transitive)

• Updated@turf/distance@^3.14.0