brush with scatterplots & sparklines

This example demonstrates how to use D3's brush component to implement focus + context zooming, with sparklines and scatterplots.

Click and drag in the small chart below to pan or zoom.

Sample data is blood pressure readings over time.

Averages for blood-pressure samples in a range are shown at the top.

Mousing over a systolic/diastolic pair highlights the pair.

Clicking on a highlighted systolic/diastolic pair opens a popup.

forked from Mike Bostock's block Focus+Context via Brushing

Thanks to Zan Armstrong for the d3 time formatting example

<!doctype html>
<head>
<meta charset='utf-8'>
<title>brush with scatterplots &amp; sparklines</title>
  
  <style>

body {
      background: #fff;
      color: #444;
      font-family: sans-serif;
      font-size: 16px;
      margin: 0;
      height: 100vh;
      width: 100vw;
    }

svg {
      margin: 0.625em;
      width: calc(100vw - 20px);
      min-width: 940px;
      height: calc(100vh - 20px);
      min-height: 480px;
    }

.focus-info {
      font-size: 0.9em;
    }

.focus .bp-line, .focus .bp-grp {
      clip-path: url(#focus-clip);
    }

.axis {
      font-size: 0.625em;
    }

.axis path, .axis line {
      fill: none;
      stroke: #444;
      shape-rendering: crispEdges;
    }

.brush .extent {
      stroke: #fff;
      fill-opacity: .125;
      shape-rendering: crispEdges;
    }

.focus .bp-grp, .close-button {
      cursor: pointer;
    }

.focus-info .bold {
      font-weight: bold;
    }

.line-arrow {
      stroke: #444;
      stroke-width: 2.5;
      marker-end: url(#line-marker);
    }

.line-marker {
      fill: #444;
      stroke: none;
    }

.popup {
      cursor: move;
    }

.popup text {
      font-size: .9em;
    }
  </style>
</head>
<body>
  <svg>
    <defs>
      <g id="close-button" transform="scale(0.15625)">
        <circle fill="darkgray" stroke="none" cx="64" cy="64" r="64"></circle>
        <rect x="16" width="96" rx="6" y="58" height="12" ry="6" transform="rotate(45 64 64)" fill="white" stroke="none"></rect>
        <rect x="16" width="96" rx="6" y="58" height="12" ry="6" transform="rotate(-45 64 64)" fill="white" stroke="none"></rect>
      </g>
      <clipPath id="focus-clip">
        <rect></rect>
      </clipPath>
      <marker id="line-marker" markerWidth="12" markerHeight="12" refX="6" refY="4" orient="auto">
        <path d="M 1 1 7 4 1 7 Z" class="line-marker"></path>
      </marker>
      <g id="line-arrow-left" transform="scale(0.5)">
        <line x1="25" x2="0" y1="10" y2="10" class="line-arrow"></line>
      </g>
      <g id="line-arrow-right" transform="scale(0.5)">
        <line x1="0" x2="25" y1="10" y2="10" class="line-arrow"></line>
      </g>
  </defs>
  </svg>
  <script src='https://cdnjs.cloudflare.com/ajax/libs/d3/3.5.5/d3.min.js'></script>
  <script src='bp-brush.js'></script>
</body>
</html>

https://cdnjs.cloudflare.com/ajax/libs/d3/3.5.5/d3.min.js