Highcharts 3.0 Bubble Chart -- Controlling bubble sizes

Question

With Highcharts 3.0 it is possible to create charts with type 'bubble', whereas prior to 3.0 it was necessary to use a 'scatter' chart and modify marker size to make bubble charts. The nice thing about the old way is you had complete control over the visible pixel radius of each bubble--the new bubble charts automatically resize the bubbles so they are sized relative to each other. Is there any way to turn off this behavior or set bubble radius manually?

Answer 1

I am having a hard time seeing how a bubble chart, where the bubbles are not sized relative to each other, would be of any use.

You should be able to use the minSize and maxSize options, however, to control them the way that you need to:

bubble: {
                minSize:2,
                maxSize:50
         }

{{edit: I don't see them in the docs either, actually. But you can see an example here: http://jsfiddle.net/fXzke/13/ use either number as pixel value, or string with percent of chart height }}

Answer 2

I found that adding an "empty" bubble to the series helps keep the size of all bubbles in the chart relative to each other:

name: '',
data: [{x:0,y:0,z:0}], 
showInLegend: false, 
color: 'transparent', 
enableMouseTracking: false

Here's a sample on JSFiddle: http://jsfiddle.net/9bebT/2/. The legend, color, and mouse tracking variables each help keep the item in the series but otherwise invisible to the user. If you simply remove the empty bubble or set its visibility to "false," the chart doesn't register the empty bubble's z axis (diameter) as the minSize.