[R] Delete rows from data.frame matching a certain criteria

[jim holtman]

Your criteria did not make sense since in both cases pattern == 1, so
I chose to set to NA if pattern == 1

> test <- data.frame(n = c(1,2,3,4,5), v = c(6,5,7,5,3), pattern =
+ c(1,1,NA,1,NA))
> test
  n v pattern
1 1 6       1
2 2 5       1
3 3 7      NA
4 4 5       1
5 5 3      NA
> # set v to NA when pattern = 1
> test$v[!is.na(test$pattern) & (test$pattern == 1)] <- NA
> test
  n  v pattern
1 1 NA       1
2 2 NA       1
3 3  7      NA
4 4 NA       1
5 5  3      NA
>
>


On Thu, Mar 1, 2012 at 11:11 AM, mails <mails00000 at gmail.com> wrote:
>
> Hello,
>
>
> consider the following data.frame:
>
> test <- data.frame(n = c(1,2,3,4,5), v = c(6,5,7,5,3), pattern =
> c(1,1,NA,1,NA))
>
> > test
>  n v pattern
> 1  1     6       1
> 2  2     5       1
> 3  3     7      NA
> 4  4     5       1
> 5  5     3      NA
>
>
> I tried to use apply and the adply function to set v to NA where pattern =
> 1
> and v to v where pattern = 1
>
>
> So basically the result should look like this:
> > test
>  n v pattern
> 1  1     NA       1
> 2  2     NA      1
> 3  3     7      NA
> 4  4     NA       1
> 5  5     3      NA
>
> So far, I solved it by creating subsets and using merge but it turns out
> to
> be super slow. Is there a way to do that
> with the apply function?
>
> Any help/hint is appreciated
>
> Thanks
>
>
> --
> View this message in context:
> http://r.789695.n4.nabble.com/Delete-rows-from-data-frame-matching-a-certain-criteria-tp4435414p4435414.html
> Sent from the R help mailing list archive at Nabble.com.
>
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--
Jim Holtman
Data Munger Guru

What is the problem that you are trying to solve?
Tell me what you want to do, not how you want to do it.