I'm seeing what looks to me like odd behaviour when I use na.omit on a
simple "length" function, as follows.
> sno
[1] 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22
23 24 25 26 27 28 29 30 31 32 33 34
> a
[1] 0 1 0 0 1 1 0 0 0 0 0 0 0 0 1 1 0 1 1 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0
> b
[1] 1 1 0 1 1 1 0 0 NA 0 0 0 NA 0 1 NA 0 1 0 0 0 0
NA 0 0 0 0 NA 0 NA 0 1 0 0
#NA refers to no data available.
> df=data.frame(sno,a,b)
# I'm pasting the sorted data frame below:
> sortdf=df[order(a,b),]
> sortdf
sno a b
3 3 0 0
7 7 0 0
8 8 0 0
10 10 0 0
11 11 0 0
12 12 0 0
14 14 0 0
17 17 0 0
20 20 0 0
21 21 0 0
22 22 0 0
24 24 0 0
25 25 0 0
26 26 0 0
27 27 0 0
29 29 0 0
31 31 0 0
33 33 0 0
34 34 0 0
1 1 0 1
4 4 0 1
9 9 0 NA
13 13 0 NA
23 23 0 NA
28 28 0 NA
30 30 0 NA
19 19 1 0
2 2 1 1
5 5 1 1
6 6 1 1
15 15 1 1
18 18 1 1
32 32 1 1
16 16 1 NA
#Now I wish to count howmany records have a=1 AND b=0. From the lower
section of that sorted dataframe we see the answer is 1 (record # 19).
But instead I'm seeing 2. Probably counting record # 16 also.
> na.omit(length(sno[a==1 & b==0]))
[1] 2
I'd be grateful to anyone who can point out what I'm doing wrong.
Regards.
______________________________________________
R-help@r-project.org mailing list
https://stat.ethz.ch/mailman/listinfo/r-help
PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
and provide commented, minimal, self-contained, reproducible code.
