Why Chart.js's tooltip appears in wrong position when mouse hover?

Question

This is my code with new version of Chart.js

<script>
    var randomScalingFactor = function(){ return Math.round(Math.random()*100)};
    var lineChartData = {
        labels : ["January","February","March","April","May","June","July","January","February","March","April","May","June","July","January","February","March","April","May","June","July","January","February","March","April","May","June","July","January","February","March","April","May","June","July","January","February","March","April","May","June","July","June","July"],
        datasets : [
            {
                label: "My First dataset",
                fillColor : "rgba(220,220,220,0.2)",
                strokeColor : "rgba(220,220,220,1)",
                pointColor : "rgba(220,220,220,1)",
                pointStrokeColor : "#fff",
                pointHighlightFill : "#fff",
                pointHighlightStroke : "rgba(220,220,220,1)",
                data : [randomScalingFactor(),randomScalingFactor(),randomScalingFactor(),randomScalingFactor(),randomScalingFactor(),randomScalingFactor(),randomScalingFactor(),randomScalingFactor(),randomScalingFactor(),randomScalingFactor(),randomScalingFactor(),randomScalingFactor(),randomScalingFactor(),randomScalingFactor(),randomScalingFactor(),randomScalingFactor(),randomScalingFactor(),randomScalingFactor(),randomScalingFactor(),randomScalingFactor(),randomScalingFactor(),randomScalingFactor(),randomScalingFactor(),randomScalingFactor(),randomScalingFactor(),randomScalingFactor(),randomScalingFactor(),randomScalingFactor(),randomScalingFactor(),randomScalingFactor(),9000,randomScalingFactor(),randomScalingFactor(),randomScalingFactor(),randomScalingFactor(),randomScalingFactor(),randomScalingFactor(),randomScalingFactor(),randomScalingFactor(),randomScalingFactor(),randomScalingFactor(),randomScalingFactor(),randomScalingFactor(),randomScalingFactor(),randomScalingFactor()]
            },
            {
                label: "My Second dataset",
                fillColor : "rgba(151,187,205,0.2)",
                strokeColor : "rgba(151,187,205,1)",
                pointColor : "rgba(151,187,205,1)",
                pointStrokeColor : "#fff",
                pointHighlightFill : "#fff",
                pointHighlightStroke : "rgba(151,187,205,1)",
                data : [randomScalingFactor(),randomScalingFactor(),randomScalingFactor(),randomScalingFactor(),randomScalingFactor(),randomScalingFactor(),randomScalingFactor(),randomScalingFactor(),randomScalingFactor(),randomScalingFactor(),randomScalingFactor(),randomScalingFactor(),randomScalingFactor(),randomScalingFactor(),20000,randomScalingFactor(),randomScalingFactor(),randomScalingFactor(),randomScalingFactor(),randomScalingFactor(),randomScalingFactor(),randomScalingFactor(),randomScalingFactor(),randomScalingFactor(),randomScalingFactor(),randomScalingFactor(),randomScalingFactor(),randomScalingFactor(),8977,randomScalingFactor(),randomScalingFactor(),randomScalingFactor(),randomScalingFactor(),randomScalingFactor(),randomScalingFactor(),randomScalingFactor(),randomScalingFactor(),randomScalingFactor(),randomScalingFactor(),randomScalingFactor(),randomScalingFactor(),randomScalingFactor(),randomScalingFactor(),randomScalingFactor(),randomScalingFactor()]
            }
        ]

    }

window.onload = function(){
    var ctx = document.getElementById("canvas").getContext("2d");
    window.myLine = new Chart(ctx).Line(lineChartData, {
        responsive: false,
        showTooltips: true,
         bezierCurve : false,
          pointDot : false,

    });
}


</script>

and the result is..

--> the red point is my mouse hover but that wrong! correct position should be black point

thank you :)

Answer 1

The default hit detection radius is a bit large. Try setting

pointHitDetectionRadius : 1,

This provides more definition on a graph with many datapoints.

Update: Fiddle