echarts环形图自动定位radius

根据后台返回数据条数进行pie图radius定位；

 

 

var a = 100;

var b = 0;

var c = 0;

var radius = [];

for (var i in data) {

a = a - 15;

 b = a - 5;

if (a < 0) { break;}

 radius.push([a + '%', b + '%']);

}