demographus demographus

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This is a little example to experiment with high-performance interactive maps. Mike Bostock has several examples of using dynamic simplification with maps, but I needed to expand on them in a few ways:

I want to change the projections on the fly, so I wanted to avoid baking a projection into my data.
I need to project the entire world instead of just one country or region.
When zooming in on an area, I wanted to avoid projecting unnecessary data. (E.g. countries outside the viewport.)

This example does all of those things. Here's an overview:

	<!DOCTYPE html>
	<html lang="en">
	<head>
	<meta charset="UTF-8">
	<title>js - isNodeList</title>
	<style>
	#y{
	color:red;
	}
	.y{

	license: gpl-3.0
	height: 600
	border: no
	redirect: https://observablehq.com/@d3/d3-versor-dragging

	#!/usr/bin/env bash

	#apt-get install -y unzip
	wget http://geolite.maxmind.com/download/geoip/database/GeoLite2-City-CSV.zip
	unzip GeoLite2-City-CSV.zip
	cd GeoLite2-City-CSV_*
	mv GeoLite2-City-Blocks-IPv4.csv /tmp/GeoLite2-City-Blocks-IPv4.csv
	mv GeoLite2-City-Locations-en.csv /tmp/GeoLite2-City-Locations-en.csv

	mysqladmin create geoip

	-- GeoLite2 CSV files for use with PostgreSQL 9+
	-- by Miles Elam <miles@geekspeak.org>

	-- THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
	-- "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
	-- LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
	-- A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
	-- OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
	-- SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
	-- LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,

	<?php

	$URIParts = explode('?',$_SERVER['REQUEST_URI']);
	$URI = explode('/',$URIParts[0]);
	// Shift the array, to move it past the 'root'
	@array_shift($URI);
	// Now, get rid of any pesky empty end slashes
	while ( @count($URI) > 0 && !end($URI) ) {
	@array_pop($URI);
	}

	/* Released under the MIT License in 2014. http://opensource.org/licenses/mit-license */

	function isNodeList(nodes) {
	var stringRepr = Object.prototype.toString.call(nodes);

	return typeof nodes === 'object' &&
	/^\[object (HTMLCollection\|NodeList\|Object)\]$/.test(stringRepr) &&
	nodes.hasOwnProperty('length') &&
	(nodes.length === 0 \|\| (typeof nodes[0] === "object" && nodes[0].nodeType > 0));
	}