<!DOCTYPE html>
<html>

<head>
    <title>Assignment1</title>
    <script src="d3.min.js"></script>
</head>

<body>
    <svg width="1600" height="800" id="mainsvg" class="svgs" style='display: block; margin: 0 auto;'></svg>
    <script>
        // The following code is the typical routine of my d3.js code. 
        const svg = d3.select('svg');
        const width = svg.attr('width');
        const height = svg.attr('height');
        const margin = { top: 60, right: 30, bottom: 60, left: 150 };
        con