Adam Roberts abenrob

## MercatorToLatLon.js
function MercatorToLatLon(mercX, mercY) {

    var rMajor = 6378137; //Equatorial Radius, WGS84
    var shift  = Math.PI * rMajor;
    var lon    = mercX / shift * 180.0;
    var lat    = mercY / shift * 180.0;
    lat = 180 / Math.PI * (2 * Math.atan(Math.exp(lat * Math.PI / 180.0)) - Math.PI / 2.0);

    return { 'Lon': lon, 'Lat': lat };
}

## LatLonToMercator.js
function LatLonToMercator(lat, lon) {

    var rMajor = 6378137; //Equatorial Radius, WGS84
    var shift  = Math.PI * rMajor;
    var x      = lon * shift / 180;
    var y      = Math.log(Math.tan((90 + lat) * Math.PI / 360)) / (Math.PI / 180);
    y = y * shift / 180;

    return {'X': x, 'Y': y};
}

## README.md

      
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                abenrob
                / README.md
            
            
              Last active
              December 19, 2015 22:09
                — forked from mbostock/.block
            
              
                Radial Area
              
          
    This plot might be suitable for showing cyclical trends, though I'm not sure it’s a great idea as the radial display has a number of limitations:


The underlying data goes from Sunday to Saturday, but the chart shows continuity from Saturday through to the previous Sunday. Time does not flow backwards, so you might instead prefer to plot two values for Sunday; this would show a discontinuity on opposite sides of the Sunday axis.


Displaying the discontinuity requires an open interpolator, rather than cardinal-closed as used here. However, this causes the tangents of the incoming and outgoing lines to no longer be orthogonal to the axis. To display the discontinuity properly, you’d need to write a custom interpolator to generate the correct tangents.


Due to the interpolation taking place in Cartesian (rather than polar) coordinates, the intermediate values of the lines do not have the correct radial values: if you tried to measure t


## index.html
<!DOCTYPE html>
<html>
  <head>
    <meta http-equiv="Content-Type" content="text/html;charset=utf-8">
    <title>Alpha-Shapes</title>
    <script src="http://mbostock.github.com/d3/d3.min.js"></script>
    <script src="http://mbostock.github.com/d3/d3.geom.min.js"></script>
    <style type="text/css">

path {
	function MercatorToLatLon(mercX, mercY) {

	var rMajor = 6378137; //Equatorial Radius, WGS84
	var shift = Math.PI * rMajor;
	var lon = mercX / shift * 180.0;
	var lat = mercY / shift * 180.0;
	lat = 180 / Math.PI * (2 * Math.atan(Math.exp(lat * Math.PI / 180.0)) - Math.PI / 2.0);

	return { 'Lon': lon, 'Lat': lat };
	}
	function LatLonToMercator(lat, lon) {

	var rMajor = 6378137; //Equatorial Radius, WGS84
	var shift = Math.PI * rMajor;
	var x = lon * shift / 180;
	var y = Math.log(Math.tan((90 + lat) * Math.PI / 360)) / (Math.PI / 180);
	y = y * shift / 180;

	return {'X': x, 'Y': y};
	}
	<!DOCTYPE html>
	<html>
	<head>
	<meta http-equiv="Content-Type" content="text/html;charset=utf-8">
	<title>Alpha-Shapes</title>
	<script src="http://mbostock.github.com/d3/d3.min.js"></script>
	<script src="http://mbostock.github.com/d3/d3.geom.min.js"></script>
	<style type="text/css">

	path {