geojson-tools - npm Package Compare versions

Comparing version 0.1.0 to 0.1.3

package.json

 {
   "name": "geojson-tools",
-  "version": "0.1.0",
+  "version": "0.1.3",
   "description": "Tools for working with location data, using the GeoJSON specification",
@@ -5,0 +5,0 @@ "main": "index.js",

README.md

@@ -1,7 +0,147 @@
-# GeoJSON-Tools
+# geojson-tools.js
 
 GeoJSON-Tools is a JavaScript module for working with location data, primarily using the GeoJSON specification.
 
-We created GeoJSON-Tools from [rwt.to](//rwt.to) in order to use it on related projects that rely on GeoJSON (primarily from MongoDB's GeoJSON support).
+We created GeoJSON-Tools from [rwt.to](//rwt.to) in order to use it on related projects that rely on GeoJSON (primarily for MongoDB's GeoJSON support).
 
-You are welcome to use it, add feature and pull requests!
+You are welcome to use it, submit bug reports, add feature and pull requests!
+
+## Installation
+
+Install [node.js](http://nodejs.org/), then:
+
+```sh
+$ npm install geojson-tools
+```
+
+## Documentation
+
+### Calculations
+
+* [getDistance](#getDistance)
+
+### Conversions
+
+* [toGeoJSON](#toGeoJSON)
+* [toArray](#toArray)
+
+## Calculations
+
+<a name="getDistance" />
+### getDistance(array, decimals [optional])
+
+Calculates the distance of an array of locations.
+
+__Arguments__
+
+* array - an array of locations, in the format `[lat, lng]`.
+* decimals - the decimal points to round answer to, defaults to 3 decimal points.
+
+__Example__
+
+```js
+var array = [
+    [20, 30],
+  [20.5, 29.5]
+];
+getDistance(array, 4);
+
+// 76.321
+```
+
+To get the distance between two points, pass two points in the array, to get the distance of a linestring, pass the coordinates of the linestring.
+
+## Conversions
+
+<a name="toGeoJSON" />
+### toGeoJSON(array, type)
+
+Takes an input of an array and a `GeoJSON` type, and returns that `GeoJSON` object.
+
+__Arguments__
+
+* array - an array of locations, in the format `[lat, lng]`.
+* type - the type of `GeoJSON` object to return (note that this is not case-sensitive.
+The default type is 'Point', which is returned when pushing an array of a single set of coordinates.
+Other types are `LineString` and `Polygon`.
+
+<b>Note:</b> Other `GeoJSON` types will be supported in future versions. 
+
+__Examples__
+
+To convert to `GeoJSON::Point`
+
+_Note that the array can be shallow or nested, but has to contain only one set of coordinates._
+```js
+var array = [[20, 30]];
+toGeoJSON(array); // or toGeoJSON(array, 'point');
+
+// {"type":"Point","coordinates":[30,20]}
+```
+
+To convert to `GeoJSON::LineString`
+```js
+var array = [
+  [20, 30],
+  [20.5, 29.5]
+];
+toGeoJSON(array, 'linestring');
+
+// {"type":"LineString","coordinates":[[30,20],[29.5,20.5]]}
+```
+
+To convert to `GeoJSON::Polygon`
+
+_The minimum number of coordinates should be 3, and there is no need to add the last coordinate in the array.._
+```js
+var array = [
+  [20, 30],
+  [20.5, 29.5],
+  [21, 30.5]
+];
+toGeoJSON(array, 'polygon');
+
+// {"type":"Polygon","coordinates":[[[[30,20],[29.5,20.5],[30.5,21],[30,20]]]]}
+```
+
+<a name="toArray" />
+### toArray(geoobj)
+
+Takes an input of a `GeoJSON` type, and returns coordinates in `[lat, lng]` format.
+A single set of coordinates for a `Point`, or an array for other types.
+
+__Arguments__
+
+* geoobj - a valid `GeoJSON` object of the following types: `Point`, `LineString` or `Polygon`.
+
+**Note:** Other `GeoJSON` types will be supported in future versions. 
+
+__Examples__
+
+To convert from `GeoJSON::Point`
+
+_Note that the array can be shallow or nested, but has to contain only one set of coordinates._
+```js
+var geoobj = {"type":"Point","coordinates":[30,20]};
+toArray(geoobj);
+
+// [20,30]
+```
+
+To convert from `GeoJSON::LineString`
+```js
+var geoobj = {"type":"LineString","coordinates":[[30,20],[29.5,20.5]]};
+toArray(geoobj);
+
+// [[20,30],[20.5,29.5]]
+```
+
+To convert from `GeoJSON::Polygon`
+
+_The minimum number of coordinates should be 3, and there is no need to add the last coordinate in the array.._
+```js
+var geoobj = {"type":"Polygon","coordinates":[[[[30,20],[29.5,20.5],[30.5,21],[30,20]]]]};
+toArray(geoobj);
+
+// [[20,30],[20.5,29.5],[21,30.5]]
+```

src/geojson-tools.js

@@ -16,3 +16,2 @@ /**
  * @param {String} type
- * @param {function} cb callback returned as cb(err, object)
  * @returns {object} GeoJSON object
@@ -78,3 +77,2 @@ */
  * @param {type} geoobj GeoJSON object
- * @param {type} cb callback with (err, result) format
  * @returns {Array}
@@ -106,3 +104,3 @@ */
     case 'polygon':
-      var array = geoobj.coordinates[0];
+      var array = geoobj.coordinates[0][0];
       var poly = [];
@@ -128,3 +126,3 @@ if (array[0].toString() !== _.last(array).toString()) {
  */
-var getDistance = function (array, dec) {
+var getDistance = function (array, decimals) {
   if(typeof(Number.prototype.toRad) === "undefined") {
@@ -136,8 +134,7 @@ Number.prototype.toRad = function () {
 
-  // a high precision is required, else the results for arrays of distances will be incorrect by magnitudes
-  var decimals = 32;
-  var earthRadius = 6378.137; // km
-
-  var distance = 0;
-  for (var i = 0; (i + 1) < array.length; i++) {
+  decimals = decimals || 3;
+  var earthRadius = 6378.137, // km
+  	distance = 0,
+  	len = array.length;
+  for (var i = 0; (i + 1) < len; i++) {
     var x1 = array[i];
@@ -160,6 +157,5 @@ var x2 = array[i + 1];
     var d = earthRadius * c;
-    var dist = Math.round(d * Math.pow(10, decimals)) / Math.pow(10, decimals);
-    distance += dist;
+    distance += d;
   }
-  distance = Math.round(distance * Math.pow(10, dec)) / Math.pow(10, dec);
+  distance = Math.round(distance * Math.pow(10, decimals)) / Math.pow(10, decimals);
   return distance;
@@ -166,0 +162,0 @@ };

No alert changes

Improved metrics

Total package byte prevSize

13590

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Number of package files

8

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Number of lines in readme file

148

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Worsened metrics

Lines of code

153

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