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<head>
  <!-- Plotly.js -->
  <script src="https://cdn.plot.ly/plotly-latest.min.js"></script>
</head>

<body>  
  <div id="myDiv" style:width: 100%><!-- Plotly chart will be drawn inside this DIV --></div>
  <script>
    <!-- JAVASCRIPT CODE GOES HERE -->
  </script>
</body>
var myPlot = document.getElementById('myDiv'),
    d3 = Plotly.d3,
    N = 16,
    x = d3.range(N),
    y = d3.range(N).map( d3.random.normal() ),
    data = [ { x:x, y:y, type:'scatter',
            mode:'markers', marker:{size:16} } ],
    layout = {
        hovermode:'closest',
        title:'Click on Points'
     };

Plotly.newPlot('myDiv', data, layout);

myPlot.on('plotly_click', function(data){
    var pts = '';
    for(var i=0; i < data.points.length; i++){
        pts = 'x = '+data.points[i].x +'\ny = '+
            data.points[i].y.toPrecision(4) + '\n\n';
    }
    alert('Closest point clicked:\n\n'+pts);
});
Rerun