Omer JR Omer JR - 18 days ago 5
R Question

replace values on condition in R

I want o replace values in two attributes in a dataframe.

CheckIn
and
CheckOut
. '--' should be replaced by NA where one of these two attribute value is missing. I tried to put some conditional logic and apply functions but failed. finally i tried using for loop.

for(i in length(Empl.A)){
if((Empl.A$CheckIn[i] == '--') & (Empl.A$CheckOut[i] == '--'))
{
Empl.A$CheckIn[i] <- NA
Empl.A$CheckOut[i] <- NA
}
}


enter image description here

please refer me to some useful resource on replacing values Or to solve these kind of problems.

Answer

You can achieve this in a vectorized way without resorting to a loop.

> xy <- data.frame(a = 1:3, ci = c("a", "--", "--"), co = c("b", "--", "--"))
> xy
  a ci co
1 1  a  b
2 2 -- --
3 3 -- --
> xy[xy$ci == "--" & xy$co == "--", c("ci", "co")] <- NA
> xy
  a   ci   co
1 1    a    b
2 2 <NA> <NA>
3 3 <NA> <NA>