Edit in JSFiddle

$(function () {
    var d1 = [];
    for (var i = 0; i < 14; i += 0.5)
        d1.push([i, Math.sin(i)]);
 
    var d2 = [[0, 3], [4, 8], [8, 5], [9, 13]];
 
    // a null signifies separate line segments
    var d3 = [[0, 12], [7, 12], null, [7, 2.5], [12, 2.5]];
    
    $.plot($("#placeholder"), [ d1, d2, d3 ]);
});
<h1>Flot Examples</h1> 
 
    <div id="placeholder" style="width:600px;height:300px;"></div>

              

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