cheap-ruler
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cheap-ruler - npm Package Compare versions
Comparing version 2.2.0 to 2.3.0
| (function(f){if(typeof exports==="object"&&typeof module!=="undefined"){module.exports=f()}else if(typeof define==="function"&&define.amd){define([],f)}else{var g;if(typeof window!=="undefined"){g=window}else if(typeof global!=="undefined"){g=global}else if(typeof self!=="undefined"){g=self}else{g=this}g.cheapRuler = f()}})(function(){var define,module,exports;return (function e(t,n,r){function s(o,u){if(!n[o]){if(!t[o]){var a=typeof require=="function"&&require;if(!u&&a)return a(o,!0);if(i)return i(o,!0);var f=new Error("Cannot find module '"+o+"'");throw f.code="MODULE_NOT_FOUND",f}var l=n[o]={exports:{}};t[o][0].call(l.exports,function(e){var n=t[o][1][e];return s(n?n:e)},l,l.exports,e,t,n,r)}return n[o].exports}var i=typeof require=="function"&&require;for(var o=0;o<r.length;o++)s(r[o]);return s})({1:[function(require,module,exports){ | ||
| 'use strict'; | ||
| 'use strict'; /* @flow */ | ||
| module.exports = cheapRuler; | ||
| function cheapRuler(lat, units) { | ||
| function cheapRuler(lat /*: number */, units /*: ?string */) { | ||
| return new CheapRuler(lat, units); | ||
| } | ||
| // unit multipliers for conversion from kilometers | ||
| var factors = { | ||
| miles: 1000 / 1609.344, | ||
| nauticalmiles: 1000 / 1852, | ||
| meters: 1000, | ||
| metres: 1000, | ||
| yards: 1000 / 0.9144, | ||
| feet: 1000 / 0.3048, | ||
| inches: 1000 / 0.0254 | ||
| }; | ||
| cheapRuler.fromTile = function (y, z, units) { | ||
@@ -20,7 +31,4 @@ var n = Math.PI * (1 - 2 * (y + 0.5) / Math.pow(2, z)); | ||
| var f = lat * Math.PI / 180; | ||
| var m = units ? factors[units] : 1; | ||
| // multiplier for unit conversion | ||
| var m = units === 'miles' ? 1.609344 : | ||
| units === 'meters' ? 1000 : 1; | ||
| // longitude correction | ||
@@ -27,0 +35,0 @@ this.kx = m * (111.41513 * Math.cos(f) - 0.09455 * Math.cos(3 * f) + 0.00012 * Math.cos(5 * f)); |
20
index.js
@@ -1,9 +0,20 @@ | ||
| 'use strict'; | ||
| 'use strict'; /* @flow */ | ||
| module.exports = cheapRuler; | ||
| function cheapRuler(lat, units) { | ||
| function cheapRuler(lat /*: number */, units /*: ?string */) { | ||
| return new CheapRuler(lat, units); | ||
| } | ||
| // unit multipliers for conversion from kilometers | ||
| var factors = { | ||
| miles: 1000 / 1609.344, | ||
| nauticalmiles: 1000 / 1852, | ||
| meters: 1000, | ||
| metres: 1000, | ||
| yards: 1000 / 0.9144, | ||
| feet: 1000 / 0.3048, | ||
| inches: 1000 / 0.0254 | ||
| }; | ||
| cheapRuler.fromTile = function (y, z, units) { | ||
@@ -19,7 +30,4 @@ var n = Math.PI * (1 - 2 * (y + 0.5) / Math.pow(2, z)); | ||
| var f = lat * Math.PI / 180; | ||
| var m = units ? factors[units] : 1; | ||
| // multiplier for unit conversion | ||
| var m = units === 'miles' ? 1.609344 : | ||
| units === 'meters' ? 1000 : 1; | ||
| // longitude correction | ||
@@ -26,0 +34,0 @@ this.kx = m * (111.41513 * Math.cos(f) - 0.09455 * Math.cos(3 * f) + 0.00012 * Math.cos(5 * f)); |
| { | ||
| "name": "cheap-ruler", | ||
| "version": "2.2.0", | ||
| "version": "2.3.0", | ||
| "description": "A collection of fast approximations to common geographic measurements.", | ||
@@ -5,0 +5,0 @@ "main": "index.js", |
@@ -1,6 +0,5 @@ | ||
| # cheap-ruler [](https://travis-ci.org/mapbox/cheap-ruler) | ||
| # cheap-ruler [](https://travis-ci.org/mapbox/cheap-ruler) [](https://github.com/mourner/projects) | ||
| A collection of fast approximations to common geographic measurements, along with some utility functions. | ||
| Useful for speeding up analysis scripts when measuring things on a city scale, | ||
| replacing [Turf](http://turfjs.org/) calls in key places. | ||
| A collection of very fast approximations to common geodesic measurements. | ||
| Useful for performance-sensitive code that measures things on a city scale. | ||
@@ -15,3 +14,3 @@ The approximations are based on an [FCC-approved formula of ellipsoidal Earth projection](https://www.gpo.gov/fdsys/pkg/CFR-2005-title47-vol4/pdf/CFR-2005-title47-vol4-sec73-208.pdf). | ||
| Compared to corresponding Turf methods (using Node v5.10): | ||
| Compared to corresponding [Turf](http://turfjs.org/) methods (using Node v5.10): | ||
@@ -38,3 +37,3 @@ - `distance`: ~26x faster | ||
| var ruler = cheapRuler(35.05, 'miles'); | ||
| // ... | ||
| var distance = ruler.distance([30.51, 50.32], [30.52, 50.312]); | ||
@@ -45,3 +44,6 @@ var lineLength = ruler.lineDistance(line.geometry.coordinates); | ||
| **Note**: to get the full performance benefit, create the ruler object once per an area of calculation (such as a tile), and then reuse it as much as possible. | ||
| **Note**: to get the full performance benefit, | ||
| create a ruler object only once per a general area of calculation, | ||
| and then reuse it as much as possible. | ||
| Don't create a new ruler for every calculation. | ||
@@ -53,3 +55,3 @@ ### Creating a ruler object | ||
| Creates a ruler object that will approximate measurements around the given latitude. | ||
| Units are either `kilometers` (default) or `miles`. | ||
| Units are one of: `kilometers` (default), `miles`, `nauticalmiles`, `meters`, `yards`, `feet`, `inches`. | ||
@@ -56,0 +58,0 @@ #### cheapRuler.fromTile(y, z[, units]) |
@@ -35,2 +35,11 @@ 'use strict'; | ||
| test('distance in miles', function (t) { | ||
| var d = ruler.distance([30.5, 32.8351], [30.51, 32.8451]); | ||
| var d2 = milesRuler.distance([30.5, 32.8351], [30.51, 32.8451]); | ||
| assertErr(t, d / d2, 1.609344, 1e-12, 'distance in miles'); | ||
| t.pass('distance in miles'); | ||
| t.end(); | ||
| }); | ||
| test('bearing', function (t) { | ||
@@ -164,8 +173,8 @@ for (var i = 0; i < points.length - 1; i++) { | ||
| var actual = milesRuler.bufferPoint(points[i], 0.1); | ||
| assertErr(t, expected[0], actual[0], 3e-5, 'bufferPoint west'); | ||
| assertErr(t, expected[1], actual[1], 3e-5, 'bufferPoint east'); | ||
| assertErr(t, expected[2], actual[2], 3e-5, 'bufferPoint south'); | ||
| assertErr(t, expected[3], actual[3], 3e-5, 'bufferPoint north'); | ||
| assertErr(t, expected[0], actual[0], 2e-7, 'bufferPoint west'); | ||
| assertErr(t, expected[1], actual[1], 2e-7, 'bufferPoint east'); | ||
| assertErr(t, expected[2], actual[2], 2e-7, 'bufferPoint south'); | ||
| assertErr(t, expected[3], actual[3], 2e-7, 'bufferPoint north'); | ||
| } | ||
| t.pass('point buffer error within 3e-5'); | ||
| t.pass('point buffer error within 2e-7'); | ||
| t.end(); | ||
@@ -172,0 +181,0 @@ }); |
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Improved metrics
- Total package byte prevSize
- increased by1.8%
46467
- Lines of code
- increased by2.81%
842
- Number of lines in readme file
- increased by1.08%
187