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

I'm struggling to understand the correct way to update a highcharts chart. Supposing I have rendered a chart, and then I want to update it in some way. For instance, I may want to change the values of the data series, or I may want to enable dataLabels.

At the moment the only way I can figure out how to do this is to alter the chart options, and use new Highcharts.chart to tell highcharts to redraw.

However, I'm wondering whether this may be overkill and it might be possible to alter the chart 'in situ', without having to start from scratch with new Highcharts.chart. I notice there is a redraw() method, but I can't seem to get it to work.

Any help is very much appreciated.

Thanks,

Robin

Sample code is as follows and at the bottom there is a jsFiddle

$(document).ready(function() {

chartOptions = {
    chart: {
        renderTo: 'container',
        type: 'area',
    },
    series: [{
        data: [1,2,3]
    }]
};

chart1 = new Highcharts.Chart(chartOptions);


chartOptions.series[0].data= [10,5,2];
chart1 = new Highcharts.Chart(chartOptions);

//The following seems to have no effect
chart1.series[0].data = [2,4,4];
chart1.redraw();

});?

http://jsfiddle.net/sUXsu/18/

[edit]:

For any future viewers of this question, it's worth noting there is no method to hide and show dataLabels. The following shows how to do it: http://jsfiddle.net/supertrue/tCF8Y/

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();

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/

@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).