na.omit in data.table，R

Question

這可能是一個潛在的錯誤，我很難用一個獨立的例子來重現它，但是，也許錯誤信息可能有助於挖掘它的底部。 miv是data.table：

> str(miv) 
Classes ‘data.table’ and 'data.frame': 113534 obs. of 21 variables: 
$ ym   : num 1980 1980 1980 1980 1980 ... 
$ dte   : Date, format: "1980-03-31" "1980-03-31" ... 
$ xs_ret  : num -16.3 -16.3 -16.3 14.3 14.3 ... 
$ xs_mkt  : num -8.85 -8.85 -8.85 12.77 12.77 ... 
$ smb   : num -7.23 -7.23 -7.23 3.62 3.62 ... 
$ hml   : num 0.966 0.966 0.966 0.318 0.318 ... 
$ umd   : num 3.713 3.713 3.713 -0.762 -0.762 ... 
$ wficn   : num 100567 101394 102565 100010 100019 ... 
$ iv_w   : num [1:113534, 1] -1.039 -0.571 -0.831 -0.357 -0.263 ... 

> miv <- na.omit(miv) 
Error in `[.data.table`(object, !omit) : 
    i is invalid type (matrix). Perhaps in future a 2 column matrix could return a list of  elements of DT (in the spirit of A[B] in FAQ 2.14). Please let datatable-help know if you'd  like this, or add your comments to FR #1611. 

Answer 1

如果它是不可重複的，它太本地化：

DT = data.table(x=rep(c("a","b","c"),each=3), y=c(1,3,6), v=1:9) 
DT[3, 2] <- NA 
DT[4, 3] <- NA 
DT 
# x y v 
#1: a 1 1 
#2: a 3 2 
#3: a NA 3 
#4: b 1 NA 
#5: b 3 5 
#6: b 6 6 
#7: c 1 7 
#8: c 3 8 
#9: c 6 9 
na.omit(DT) 
# x y v 
#1: a 1 1 
#2: a 3 2 
#3: b 3 5 
#4: b 6 6 
#5: c 1 7 
#6: c 3 8 
#7: c 6 9