c3.js - c3js bar width not adjusting to the zooming -

the chart pretty when normal. expect adjust bar width upon zoom. graph without zoom below.

when zoom graph, bars width remains same, thin!

is there anyway auto adjust? saw link example adjusts bar width zoom. don't see missing. here's example : http://blog.trifork.com/2014/07/29/creating-charts-with-c3-js/

here's charting code. missing setting?

var chart = c3.generate({     bindto: '#chart',     data: {         xformat: '%m/%d/%y %i:%m %p',         json: final_data,         keys: {             x: 'date',             value: values         },         type: 'bar',         groups: val     },     bar: {         width: { ratio: 0.9 }     },     axis: {         x: {             type: 'timeseries',             tick: {                 format: '%b %d'             }         }     },     zoom: {         enabled: true     },     color: {         pattern: colors     } }); 

try removing key value pair "bar". if problem still persists, try setting axis.x.tick.fit = false