p2p按年化率计算收益简单算法

public class Arith{

public double computeIncomeAmount(){
double incomeAmount = 0.00;// 标的收益

double apr=15 //年化率

int periodUnit =0 //-1：天标 0：月标 1：年标

int period=1  //投资期限

switch (periodUnit) {
case -1:
incomeAmount = Arith.round(apr / 100 * period * investAmount, 2);
break;
case 0:
incomeAmount = Arith.round(apr / 12 / 100 * period * investAmount,
2);
break;
case 1:
incomeAmount = Arith.round(apr / 360 / 100 * period * investAmount,
2);
break;
}
return incomeAmount;
}
/**
* 功能：提供精确的小数位四舍五入处理。
* @param v 需要四舍五入的数字
* @param scale 小数点后保留几位
* @return 四舍五入后的结果
*/
public static double round(double v, int scale) {
if (scale < 0) {
throw new IllegalArgumentException("精确度不能小于0！");

}

BigDecimal b = new BigDecimal(Double.toString(v));

return b.setScale(scale,BigDecimal.ROUND_HALF_UP).doubleValue();
}

}