用try..catch，异常抛出return double()就可以了，如下：
t1 = select * from table_raw where date>2021.12.08
def myols(y,x) {
r=ols(y,x,true,2)
try {return r.RegressionStat.statistics[1]} catch(ex) {return double()}
}
select myols(price, volume) as r2 from t1 group by date, wind_code