[Solved]-Highcharts - redraw() vs. new Highcharts.chart-Highcharts

@RobinL as mentioned in previous comments, you can use chart.series[n].setData(). First you need to make sure you’ve assigned a chart instance to the chart variable, that way it adopts all the properties and methods you need to access and manipulate the chart.

I’ve also used the second parameter of setData() and had it false, to prevent automatic rendering of the chart. This was because I have multiple data series, so I’ll rather update each of them, with render=false, and then running chart.redraw(). This multiplied performance (I’m having 10,000-100,000 data points and refreshing the data set every 50 milliseconds).

var newData = [1,2,3,4,5,6,7];
var chart = $('#chartjs').highcharts();
chart.series[0].setData(newData, true);

Explanation:
Variable newData contains value that want to update in chart. Variable chart is an object of a chart. setData is a method provided by highchart to update data.

Method setData contains two parameters, in first parameter we need to pass new value as array and second param is Boolean value. If true then chart updates itself and if false then we have to use redraw() method to update chart (i.e chart.redraw();)

http://jsfiddle.net/NxEnH/8/

you have to call set and add functions on chart object before calling redraw.

chart.xAxis[0].setCategories([2,4,5,6,7], false);

chart.addSeries({
    name: "acx",
    data: [4,5,6,7,8]
}, false);

chart.redraw();