- drop if date=="3/31/2013"
- drop if date=="3/31/2014"
- drop if date=="3/31/2015"
- drop if date=="3/31/2016"
- drop if date=="3/31/2017"
- drop if date=="3/31/2018"
- drop if date=="6/30/2013"
- drop if date=="6/30/2014"
- drop if date=="6/30/2015"
- drop if date=="6/30/2016"
- drop if date=="6/30/2017"
- drop if date=="6/30/2018"
- drop if date=="9/30/2013"
- drop if date=="9/30/2014"
- drop if date=="9/30/2015"
- drop if date=="9/30/2016"
- drop if date=="9/30/2017"
- drop if date=="9/30/2018"
复制代码我写的代码如上,想去掉除了12-31的利润数据,可是用上面的代码删除不了,0 observations deleted