Google Charts Stacked bar格式和数据之间的间距

Question

我使用此参数创建图表图像

    $params['cht']= 'bvs';//Chart Type
    $params['chd'] = "t:";
    $params['chd'].=$finaldata;//
    $params['chm']= 'N,FF0000,-1,,12|N,000000,0,,14,,c|N,000000,1,,14,,c|N,000000,2,,14,,c';
    $params['chs'] = $this->getWidth().'x'.$this->getHeight();// chart size
    $params['chco'] = '4d89f9,C6D9FD,FF0000';//series color
    $params['chbh'] = '80,20';//bar width and space
    $params['chds'] = 'a';//$min_amount.','.$max_amount;//scaling for min and max amount
    $params['chxt'] ='x';//visible axis
    $params['chxr'] ='0,'.$min_value.','.$max_value;
    $params['chg'] ='10,20';//Grid lines background

我使用google Visualization api创建Stacked条形图。 我想以清晰和适当的间距显示数据，坚持2天。谢谢你的帮助。