score:28

Accepted answer

you can't just set the value. chart.series[0].data[0] returns a point object, which you can then use it's 'update' method to change it's values.

chart.series[0].data[0].update(y += 10); 

you can see an example here: http://jsfiddle.net/gh/get/jquery/1.7.2/highslide-software/highcharts.com/tree/master/samples/highcharts/members/point-update-column/

score:11

well it works properly for both coordinates: http://jsfiddle.net/psbh7/

 chart.series[0].data[0].update({
                x:20
            }); 

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