extjs4.1 - How to customize the shape of a column chart in extjs -

can tell me how customize shape of column chart in extjs? default column chart top edge or corner appears flat. want display rounded corners top edges.

any highly appreciated.

thanks

i don't think can without rewriting parts of bar chart code. can define renderer series follows:

series: [{     renderer: function(sprite, record, barattr, index, store){         barattr.radius=5;         return barattr;     }, ... 

but make corners rounded. sprite type bar charts hard coded 'rect' in bar.js drawseries, , can't semi rounded. may want rewrite 'path' sprite. love know of better solution..