Using the dplyr library in R to “print” the name of the non-NA columns

6

Here is my data frame:

a <- data.frame(id=c(rep("A",2),rep("B",2)),
                x=c(rep(2,2),rep(3,2)),
                p.ABC= c(1,NA,1,1),
                p.DEF= c(NA,1,NA,NA),
                p.TAR= c(1,NA,1,1),
                p.REP= c(NA,1,1,NA),
                p.FAR= c(NA,NA,1,1))

I Want to create a new character column (using mutate() in the dplyr library in R), which tells (by row) the name of the columns that have a non-NA value (here the non-NA value is always 1). However, it should only search among the columns that start with "p." and it should order the names by alphabetical order and then concatenate them using the expression "_" as a separator. You can find below the desired result, under the column called "name":

data.frame(id=c(rep("A",2),rep("B",2)),
                x=c(rep(2,2),rep(3,2)),
                p.ABC= c(1,NA,1,1),
                p.DEF= c(NA,1,NA,NA),
                p.TAR= c(1,NA,1,1),
                p.REP= c(NA,1,1,NA),
                p.FAR= c(NA,NA,1,1),
                name=c("ABC_TAR","DEF_REP","ABC_FAR_REP_TAR","ABC_FAR_TAR"))

I would like to emphasize that I'm really looking for a solution using dplyr, as I would be able to do it without it (but it doesn't look pretty and it's slow).

r dplyr

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asked Apr 17 at 22:32

Anthony HauserAnthony Hauser

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