CB terbo

How a Quadtree is created

This demo shows an animation explaining how a Quadtree is created using D3: "A quadtree is a two-dimensional recursive spatial subdivision. This implementation uses square partitions, dividing each square into four equally-sized squares."

The demo was inspired by the article on Visualizing Algorithms. To draw the points and the quadtree squares I took some code from this Example. The tree basically reuses the code of this Example.

This example is inspired by Calendar View and Trulia Trends. You can toggle the displaying type to see either the level of values or change trends in each day. Thank air-scientific.com for the pm2.5 data.

	Function Get-WinEventTail
	{
	<#
	.SYNOPSIS
	A tail cmdlet for Eventlogs
	.DESCRIPTION
	This function will allow you to tail Windows Event Logs. You specify
	a Logname for either the original logs, Application, System and Security or
	the new format for the newer logs Microsoft-Windows-PowerShell/Operational
	.PARAMETER LogName

	var dat=dat\|\|{};dat.gui=dat.gui\|\|{};dat.utils=dat.utils\|\|{};dat.controllers=dat.controllers\|\|{};dat.dom=dat.dom\|\|{};dat.color=dat.color\|\|{};dat.utils.css=function(){return{load:function(e,a){a=a\|\|document;var b=a.createElement("link");b.type="text/css";b.rel="stylesheet";b.href=e;a.getElementsByTagName("head")[0].appendChild(b)},inject:function(e,a){a=a\|\|document;var b=document.createElement("style");b.type="text/css";b.innerHTML=e;a.getElementsByTagName("head")[0].appendChild(b)}}}();
	dat.utils.common=function(){var e=Array.prototype.forEach,a=Array.prototype.slice;return{BREAK:{},extend:function(b){this.each(a.call(arguments,1),function(a){for(var f in a)this.isUndefined(a[f])\|\|(b[f]=a[f])},this);return b},defaults:function(b){this.each(a.call(arguments,1),function(a){for(var f in a)this.isUndefined(b[f])&&(b[f]=a[f])},this);return b},compose:function(){var b=a.call(arguments);return function(){for(var d=a.call(arguments),f=b.length-1;0<=f;f--)d=[b[f].apply(this,d)];return d[0]}},
	each:function(a,d,f){if(e&