New @turf/isolines based on MarchingSquares.js

packages/turf-isolines/README.md

@@ -7,10 +7,13 @@ value breaks and generates [isolines](http://en.wikipedia.org/wiki/Isoline).
 
 **Parameters**
 
-- `points` **[FeatureCollection](http://geojson.org/geojson-spec.html#feature-collection-objects)<[Point](http://geojson.org/geojson-spec.html#point)>** input points
-- `z` **[string](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/String)** the property name in `points` from which z-values will be pulled
-- `resolution` **[number](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Number)** resolution of the underlying grid
+- `points` **[FeatureCollection](http://geojson.org/geojson-spec.html#feature-collection-objects)<[Point](http://geojson.org/geojson-spec.html#point)>** a FeatureCollection of [Point](http://geojson.org/geojson-spec.html#point) features
 - `breaks` **[Array](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array)<[number](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Number)>** where to draw contours
+- `zProperty` **\[[string](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/String)]** the property name in `points` from which z-values will be pulled (optional, default `'elevation'`)
+- `options` **\[[Object](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object)]** options on output (optional, default `{}`)
+ - `options.isolineProperties` **\[[Array](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array)<[Object](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object)>]** GeoJSON properties passed, in order, to the correspondent
+ isoline (order defined by breaks) (optional, default `[]`)
+ - `options.commonProperties` **\[[Object](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object)]** GeoJSON properties passed to ALL isolines (optional, default `{}`)
 
 **Examples**
 

packages/turf-isolines/bench.js

@@ -1,18 +1,65 @@
-var isolines = require('./');
-var Benchmark = require('benchmark');
-var fs = require('fs');
+const path = require('path');
+const Benchmark = require('benchmark');
+const load = require('load-json-file');
+const fs = require('fs');
+const matrixToGrid = require('matrix-to-grid');
+const isolines = require('./');
 
-var points = JSON.parse(fs.readFileSync(__dirname+'/test/Points.geojson'));
+// Define Fixtures
+const directory = path.join(__dirname, 'test', 'in') + path.sep;
+const fixtures = fs.readdirSync(directory).map(filename => {
+ return {
+ filename,
+ name: path.parse(filename).name,
+ jsondata: load.sync(directory + filename)
+ };
+});
 
-var suite = new Benchmark.Suite('turf-isolines');
+/**
+ * Benchmark Results
+ *
+ * bigMatrix x 168 ops/sec ±2.79% (72 runs sampled)
+ * matrix1 x 17,145 ops/sec ±4.73% (68 runs sampled)
+ * matrix2 x 11,004 ops/sec ±2.56% (79 runs sampled)
+ * pointGrid x 12,109 ops/sec ±2.01% (77 runs sampled)
+ */
+const suite = new Benchmark.Suite('turf-isolines');
+for (const {name, jsondata, filename} of fixtures) {
+
+ let breaks, points, zProperty, isolineProperties, commonProperties;
+ // allow geojson featureCollection...
+ if (filename.includes('geojson')) {
+ breaks = jsondata.properties.breaks;
+ zProperty = jsondata.properties.zProperty;
+ commonProperties = jsondata.properties.commonProperties;
+ isolineProperties = jsondata.properties.isolineProperties;
+ points = jsondata;
+ } else {
+ // ...or matrix input
+ const matrix = jsondata.matrix;
+ const cellSize = jsondata.cellSize;
+ const origin = jsondata.origin;
+ breaks = jsondata.breaks;
+ zProperty = jsondata.zProperty;
+ points = matrixToGrid(matrix, origin, cellSize, {zProperty, units: jsondata.units});
+ commonProperties = jsondata.commonProperties;
+ isolineProperties = jsondata.isolineProperties;
+ }
+
+ isolines(points, breaks, zProperty, {
+ commonProperties,
+ isolineProperties
+ });
+
+ // isolines(geojson, 'elevation', [5, 45, 55, 65, 85, 95, 105, 120, 180]);
+ suite.add(name, () => isolines(points, breaks, zProperty, {
+ commonProperties,
+ isolineProperties
+ })
+ );
+}
 suite
- .add('turf-isolines',function () {
- isolines(points, 'elevation', 15, [25, 45, 55, 65, 85, 95, 105, 120, 180]);
- })
- .on('cycle', function (event) {
- console.log(String(event.target));
- })
- .on('complete', function () {
-
- })
+ .on('cycle', e => console.log(String(e.target)))
+ .on('complete', () => {})
  .run();
+