if and & statement in R

Question

I have a data.frame with 4 columns like that:

> bb
               V1      V2      V3       V4
1         ARFGEF2 ARFGEF2 ARFGEF2     <NA>
2           SFRS5    <NA>   SRSF5     <NA>
3 ENSG00000215104    <NA>    <NA> CHMP1B2P
4            EDF1    EDF1    EDF1     <NA>
5    LOC100133678    <NA>    <NA>     <NA>
6            CD3G    CD3G       -     <NA>
7           GNAI2   GNAI2   GNAI2     <NA>

I want to create a new column according to values on columns 2, 3, and 4. What I was trying to do is : If bb[,2] is a NA AND bb[,3] has a value then bb[,5] would be the value of bb[,3], if bb[,2] is a NA AND bb[,3] is a NA and df[,4] has a value then bb[,5] would be the value of bb[,4], else bb[,5] would be df[,1]. Here is the expected output:

> bb
                V1      V2      V3       V4       V5
1          ARFGEF2 ARFGEF2 ARFGEF2     <NA>  ARFGEF2
2            SFRS5    <NA>   SRSF5     <NA>    SRSF5
3  ENSG00000215104    <NA>    <NA> CHMP1B2P CHMP1B2P
4             EDF1    EDF1    EDF1     <NA>     EDF1
5     LOC100133678    <NA>    <NA>     <NA>     <NA>
6             CD3G    CD3G       -     <NA>        -
7            GNAI2   GNAI2   GNAI2     <NA>    GNAI2

I've trying this code but it doesn't work:

> for (i in 1:nrow(bb)){
      if (is.na(bb[i,2] & !(is.na(bb[i,3])))) {bb[i,5] <- as.character(bb[i,3])}
    else if (is.na(bb[i,2]) & !(is.na(bb[i,4]))) {bb[i,5] <- as.character(bb[i,4])}
    else { bb[i,5] <- bb[i,1]}
}
Warning messages:
 1: In Ops.factor(bb[i, 2], !(is.na(bb[i, 3]))) :
  & not meaningful for factors
 2: In Ops.factor(bb[i, 2], !(is.na(bb[i, 3]))) :
  & not meaningful for factors
 3: In Ops.factor(bb[i, 2], !(is.na(bb[i, 3]))) :
  & not meaningful for factors
 4: In Ops.factor(bb[i, 2], !(is.na(bb[i, 3]))) :
  & not meaningful for factors
 5: In Ops.factor(bb[i, 2], !(is.na(bb[i, 3]))) :
  & not meaningful for factors
 6: In Ops.factor(bb[i, 2], !(is.na(bb[i, 3]))) :
  & not meaningful for factors
 7: In Ops.factor(bb[i, 2], !(is.na(bb[i, 3]))) :
  & not meaningful for factors

How could I use & with the if statement? This is an example of a much longer data.frame where I would like to create a new column (V5) taking the values of V1 if V2 is not a NA. In case of V2 being a NA, first I want to check whether V3 has a value and if it is TRUE then V5 would be V3 value, second, if V3 is a NA and V4 has a value then V5 would be the value of V4, finally if V3 and V4 are NA then V5 would be V1.

Many thanks

Answer 1

Your for loop should be using && instead of &. Also a missing bracket at the first is.na. But try the ifelse function, something along the lines

bb[,5] <- ifelse(is.na(bb[,2]) & !is.na(bb[,3]), 
            bb[,3], 
            ifelse(is.na(bb[,2]) & !is.na(bb[,4]), bb[,4], bb[,1])
          )

(untested)