<!DOCTYPE html>
<html lang="en">
    <head>
        <meta charset="utf-8">
        <title>D3 Test</title>
        <script type="text/javascript" src="https://cdnjs.cloudflare.com/ajax/libs/d3/4.7.0/d3.min.js"></script>
        <style type="text/css">
            
        </style>
    </head>
    <body>
        
        <script type="text/javascript">
            var w = 512;
            var h = 512;
            var numBoxes = 128;
            var boxSize = w / numBoxes;


            var dataset = [];
     