On Nov 8, 2009, at 11:08 AM, David Winsemius wrote:
On Nov 8, 2009, at 10:23 AM, Ashta wrote:
HI R-Users
Assume that I have a data frame 'temp' with several variables
(v1,v2,v3,v4,v5.).
v1 v2 v3 v4 v5
1 2 3 3 6
5 2 4 2 0
2 -9 5 4 3
6 2 1 3 4
1, I want to look at the entire row values of when v2 =-9
like
2 -9 5 4 3
I wrote
K<- list(if(temp$v2)==-9))
A further thought, that might be more useful if you were intending to
supply a portion of a dataframe to an analytical function, would be
the subset function:
t2 <- subset(temp, v2 != -9)
E. g.:
lm( v1 ~ v2 + v3, data= subset(temp, v2 != -9)
"if" would be the wrong R function to use. It's mostly for program
control. And where did the "3" come from? You were working with the
column temp$v2. Oh, you wanted a row rather than the column, "v2"?
So how were you going to select that row? Perhaps:
K <-temp[ temp$v2 == -9, ]
K
I wrote the like this but it gave me which is not correct.
False false false false false
I could not get your code to produce this. I got:
Error: unexpected '==' in "K<- list(if(temp$v2)=="
2. I want assign that values as missing if v2 = -9. (ie., I want
exclude from the analysis
How do I do it in R?
Your request is not well specified at least to my reading, because I
could not tell if you wanted the re-assignment to occur in temp (and
that was after I came down on the row side of the whether you wanted
a row or column.) . The following assumes you wanted the row in
question (created above) modified outside of "temp".
> is.na(K) <- K == -9
> K
v1 v2 v3 v4 v5
3 2 NA 5 4 3
If you had used ifelse you would have gotten close, but the data
type would have been a list, which may not have been what you
expected:
> K <- ifelse(K==-9, NA, K)
> K
[[1]]
[1] 2
[[2]]
[1] NA
[[3]]
[1] 5
[[4]]
[1] 4
[[5]]
[1] 3
--
David Winsemius, MD
Heritage Laboratories
West Hartford, CT
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David Winsemius, MD
Heritage Laboratories
West Hartford, CT
______________________________________________
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.
