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<title>Flot Examples</title>
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<h1>Flot Examples</h1>
<div id="placeholder" style="width:600px;height:300px"></div>
<p>You can add crosshairs that'll track the mouse position, either
on both axes or as here on only one.</p>
<p>If you combine it with listening on hover events, you can use
it to track the intersection on the curves by interpolating
the data points (look at the legend).</p>
<p id="hoverdata"></p>
<script type="text/javascript">
var plot;
$(function () {
var sin = [], cos = [];
for (var i = 0; i < 14; i += 0.1) {
sin.push([i, Math.sin(i)]);
cos.push([i, Math.cos(i)]);
}
plot = $.plot($("#placeholder"),
[ { data: sin, label: "sin(x) = -0.00"},
{ data: cos, label: "cos(x) = -0.00" } ], {
series: {
lines: { show: true }
},
crosshair: { mode: "x" },
grid: { hoverable: true, autoHighlight: false },
yaxis: { min: -1.2, max: 1.2 }
});
var legends = $("#placeholder .legendLabel");
legends.each(function () {
// fix the widths so they don't jump around
$(this).css('width', $(this).width());
});
var updateLegendTimeout = null;
var latestPosition = null;
function updateLegend() {
updateLegendTimeout = null;
var pos = latestPosition;
var axes = plot.getAxes();
if (pos.x < axes.xaxis.min || pos.x > axes.xaxis.max ||
pos.y < axes.yaxis.min || pos.y > axes.yaxis.max)
return;
var i, j, dataset = plot.getData();
for (i = 0; i < dataset.length; ++i) {
var series = dataset[i];
// find the nearest points, x-wise
for (j = 0; j < series.data.length; ++j)
if (series.data[j][0] > pos.x)
break;
// now interpolate
var y, p1 = series.data[j - 1], p2 = series.data[j];
if (p1 == null)
y = p2[1];
else if (p2 == null)
y = p1[1];
else
y = p1[1] + (p2[1] - p1[1]) * (pos.x - p1[0]) / (p2[0] - p1[0]);
legends.eq(i).text(series.label.replace(/=.*/, "= " + y.toFixed(2)));
}
}
$("#placeholder").bind("plothover", function (event, pos, item) {
latestPosition = pos;
if (!updateLegendTimeout)
updateLegendTimeout = setTimeout(updateLegend, 50);
});
});
</script>
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