Re: Substituting numerical values using `apply'

> Try this:
>
> sapply(names(DF), function(n)ifelse(DF[,n] %in% c(1, 2), n, NA))
>
> Where DF is your data.frame
>
> On Wed, Jul 8, 2009 at 5:25 PM, Olivella <olivella@...
> <mailto:olivella@...>> wrote:
>
>
>     Hello,
>
>     I wish to perform a substitution of certain numerical values in a data
>     matrix with the corresponding column name. For instance, if I have
>     a data
>     matrix
>     V1  V2  V3
>     2    0    1
>     0    1    2
>     1    5    0
>     5    0    0
>
>     I want to substitute the `1' and the `2' for the corresponding
>     column name,
>     and make everything else `NA' like this
>     V1    V2    V3
>     V1    NA    V3
>     NA    V2    V3
>     V1    NA    NA
>     NA    NA    NA
>
>     I have done this using an explicit `for' loop, but it takes a
>     really long
>     time to finish. Is there any way I can do this using `apply' or
>     some form of
>     implicit looping?
>
>     Thank you for your help,
>
>     SO
>     --
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>
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>
>
> --
> Henrique Dallazuanna
> Curitiba-Paraná-Brasil
> 25° 25' 40" S 49° 16' 22" O