On 25/01/2011 8:07 p.m., typhoong wrote:
hi i have the following dataframe
x y
1 345
6 NA
8 123
32 123
12 NA
6 124
7 NA
and i want to extract the data rows which contains "NA" data, I tried
subset(dataframe,y=="NA")
but fail. if you know the answers, please let me know thanks.
typhoong
Your test is wrong for NA. You must use is.na:
> df
x y
1 1 345
2 6 NA
3 8 123
4 32 123
5 12 NA
6 6 124
7 7 NA
> subset(df, is.na(y))
x y
2 6 NA
5 12 NA
7 7 NA
--
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