How to change column width one by one in extjs columns chart?

How to change column width of a columns chart on开发者_运维百科e by one? I need charts like this:

 _          __
| |  ____  |  |
| | |    | |  |
| | |    | |  |
|_| |____| |__|

...

series: [
     {
             type: 'column',
             axis: 'left',
             gutter: 10,
             style: {
                   width: 50    //<-- Specify you Column width here
             },
             xField: 'title',                            
             yField: ['totaltodotime', 'workdone'],
             stacked: true,
...

• Ext JS documentation (http://docs.sencha.com/ext-js/4-0/#!/api/Ext.chart.series.Column-cfg-style) for Chart Series column has style as one of the configuration option.
• I added width attribute followed by required size.

renderer: function(sprite, record, attr, index, store) {                       
                        var color = selectedColor;
                        if (unique condition to identify the column ) {
                            return Ext.apply(attr, {
                                fill: color,
                                width: 100,x:50,y:50

                            });

                        }
                        else(another condition) {
                            return Ext.apply(attr, {
                                fill: color
                                ,width: 50,

                            });
                        }

                    },
you can use record or index or store to identify the column being rendered