@turf/idw - npm Package Compare versions

Comparing version 4.4.0 to 4.5.1

index.d.ts

@@ -8,6 +8,6 @@ /// <reference types="geojson" />
 /**
- * http://turfjs.org/docs/
+ * http://turfjs.org/docs/#idw
  */
-declare function idw(controlPoints: Points, valueField: string, b: number, cellWidth: number, units?: Units): Polygons;
+declare function idw(controlPoints: Points, valueField: string, weight: number, cellWidth: number, units?: Units): Polygons;
 declare namespace idw { }
 export = idw;

index.js

@@ -0,5 +1,5 @@
+var bbox = require('@turf/bbox');
 var distance = require('@turf/distance');
+var centroid = require('@turf/centroid');
 var squareGrid = require('@turf/square-grid');
-var centroid = require('@turf/centroid');
-var bbox = require('@turf/bbox');
 
@@ -16,9 +16,14 @@ /**
  * @param {string} valueField GeoJSON field containing the known value to interpolate on
- * @param {number} b Exponent regulating the distance-decay weighting
+ * @param {number} weight Exponent regulating the distance-decay weighting
  * @param {number} cellWidth The distance across each cell
  * @param {string} [units=kilometers] used in calculating cellSize, can be degrees, radians, miles, or kilometers
- * @returns {FeatureCollection<Polygon>} grid A grid of polygons with a property field "IDW"
+ * @returns {FeatureCollection<Polygon>} grid A grid of polygons with a property field named as `valueField`
  */
-module.exports = function (controlPoints, valueField, b, cellWidth, units) {
-    // check if field containing data exists..
+module.exports = function (controlPoints, valueField, weight, cellWidth, units) {
+    // validation
+    if (!valueField) throw new Error('valueField is required');
+    if (weight === undefined || weight === null) throw new Error('weight is required');
+    if (cellWidth === undefined || cellWidth === null) throw new Error('cellWidth is required');
+
+    // check if field containing data exists.
     var filtered = controlPoints.features.filter(function (feature) {
@@ -28,27 +33,25 @@ return feature.properties &&
     });
-    if (filtered.length !== 0) {
-      // create a sample square grid
-      // compared to a point grid helps visualizing the output (like a raster..)
-        var samplingGrid = squareGrid(bbox(controlPoints), cellWidth, units);
-        var N = samplingGrid.features.length;
-        for (var i = 0; i < N; i++) {
-            var zw = 0;
-            var sw = 0;
-            // calculate the distance from each control point to cell's centroid
-            for (var j = 0; j < controlPoints.features.length; j++) {
-                var d = distance(centroid(samplingGrid.features[i]), controlPoints.features[j], units);
-                if (d === 0) {
-                    zw = controlPoints.features[j].properties[valueField];
-                }
-                var w = 1.0 / Math.pow(d, b);
-                sw += w;
-                zw += w * controlPoints.features[j].properties[valueField];
+    if (filtered.length === 0) throw new Error('Specified Data Field is Missing');
+
+    // create a sample square grid
+    // compared to a point grid helps visualizing the output (like a raster..)
+    var samplingGrid = squareGrid(bbox(controlPoints), cellWidth, units);
+    var N = samplingGrid.features.length;
+    for (var i = 0; i < N; i++) {
+        var zw = 0;
+        var sw = 0;
+        // calculate the distance from each control point to cell's centroid
+        for (var j = 0; j < controlPoints.features.length; j++) {
+            var d = distance(centroid(samplingGrid.features[i]), controlPoints.features[j], units);
+            if (d === 0) {
+                zw = controlPoints.features[j].properties[valueField];
             }
-            // write IDW value for each grid cell
-            samplingGrid.features[i].properties.z = zw / sw;
+            var w = 1.0 / Math.pow(d, weight);
+            sw += w;
+            zw += w * controlPoints.features[j].properties[valueField];
         }
-        return samplingGrid;
-    } else {
-        console.log('Specified Data Field is Missing');
+        // write IDW value for each grid cell
+        samplingGrid.features[i].properties[valueField] = zw / sw;
     }
+    return samplingGrid;
 };

package.json

 {
   "name": "@turf/idw",
-  "version": "4.4.0",
+  "version": "4.5.1",
   "description": "turf idw module",
@@ -20,2 +20,6 @@ "main": "index.js",
   "author": "Turf Authors",
+  "contributors": [
+    "Stefano Borghi <@stebogit>",
+    "Denis Carriere <@DenisCarriere>"
+  ],
   "license": "MIT",
@@ -27,2 +31,3 @@ "bugs": {
   "devDependencies": {
+    "@turf/helpers": "^4.5.1",
     "benchmark": "^2.1.4",
@@ -34,7 +39,7 @@ "load-json-file": "^2.0.0",
   "dependencies": {
-    "@turf/bbox": "^4.4.0",
-    "@turf/centroid": "^4.4.0",
-    "@turf/distance": "^4.4.0",
-    "@turf/square-grid": "^4.4.0"
+    "@turf/bbox": "^4.5.1",
+    "@turf/centroid": "^4.5.1",
+    "@turf/distance": "^4.5.1",
+    "@turf/square-grid": "^4.5.1"
   }
 }

README.md

@@ -14,7 +14,7 @@ # @turf/idw
 -   `valueField` **[string](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/String)** GeoJSON field containing the known value to interpolate on
--   `b` **[number](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Number)** Exponent regulating the distance-decay weighting
+-   `weight` **[number](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Number)** Exponent regulating the distance-decay weighting
 -   `cellWidth` **[number](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Number)** The distance across each cell
 -   `units` **\[[string](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/String)]** used in calculating cellSize, can be degrees, radians, miles, or kilometers (optional, default `kilometers`)
 
-Returns **[FeatureCollection](http://geojson.org/geojson-spec.html#feature-collection-objects)<[Polygon](http://geojson.org/geojson-spec.html#polygon)>** grid A grid of polygons with a property field "IDW"
+Returns **[FeatureCollection](http://geojson.org/geojson-spec.html#feature-collection-objects)<[Polygon](http://geojson.org/geojson-spec.html#polygon)>** grid A grid of polygons with a property field named as `valueField`
 
@@ -21,0 +21,0 @@ <!-- This file is automatically generated. Please don't edit it directly:

No alert changes

Improved metrics

Total package byte prevSize

7363

increased by5.17%

Lines of code

62

increased by1.64%

Worsened metrics

Dev dependency count

5

increased by25%

Dependency changes

• Updated@turf/bbox@^4.5.1

• Updated@turf/centroid@^4.5.1

• Updated@turf/distance@^4.5.1

• Updated@turf/square-grid@^4.5.1