-- Create a div where the graph will take place -->
<div id="my_dataviz"></div>
</xmp></code></pre>
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<!-- ========= show JS code V4 ==============  -->
<pre class="language-js d-none d3v4-chunk"><code id="code-js-v4" contenteditable="true"><xmp><script>

// set the dimensions and margins of the graph
var margin = {top: 20, right: 30, bottom: 20, left: 30},
  width = 450 - margin.left - margin.right,
  height = 300 - margin.top - margin.bottom;

// append the sv