公式（大单净量）显示错误改正的方法

X1:ZDMR+BDMR;
y1:=-(ZDMC+BDMC);
STICKLINE(x1+y1>=0,5*(x1+y1),0,8,0),colorred;
STICKLINE(x1+y1<0,5*(x1+y1),0,8,0),colorgreen;
a=(ZDMR[-1]+BDMR[-1]);
b=(ZDMC[-1]+BDMC[-1]);
a3=SUM(a,1)/1000000;
b3=SUM(b,1)/1000000;
VOL1=SUM(VOL,1)/1000000;
IF(a3>b3)
{
y=a3-b3;
z=y/VOL1*100;
大单净量统计:TOSTRING(1,0)+"天机构买入"+TOSTRING(a3,1)+"万手,净卖出"+TOSTRING(b3,1)+"万手.净卖出"+TOSTRING(y,1)+"万手.占总成交"+TOSTRING(z,1)+"％.";
}
ELSE
{
y=b3-a3;
z=y/VOL1*100;
统计:TOSTRING(1,0)+"天机构买入"+TOSTRING(a3,1)+"万手,净卖出"+TOSTRING(b3,1)+"万手.净买入"+TOSTRING(y,1)+"万手.占总成交"+TOSTRING(z,1)+"％.";
END;