I want to add new column to my dataframe that only has two values ,1 and 0. 1 if either of the x, y, and z columns have an instance of 1, and 0 otherwise. For instance, with this rule, all but rows 6 and 9 have new column value as 1. But, my code does not work in this way.

I would appreciate if someone could help me on this.

set.seed(1)
x <- sample(1:3, 10, replace = TRUE)
y <- sample(1:3, 10, replace = TRUE)
z <- sample(1:3, 10, replace = TRUE)
df <- data.frame(x,y,z)

for (i in 1:nrow(df)){
  if ((df$x[i] == 1)== TRUE | (df$y[i] == 1) == TRUE | (df$z[i] == 1) == TRUE){
    df$new <- 1
  }
  else{
    df$new <- 0
  }
}

>Solution :

You’ll need indices on your new-variable. Note though that there are faster ways to achieve this end using the apply-family instead of a loop (I am sure other’s will post these).

for (i in 1:nrow(df)){
  if ((df$x[i] == 1) | (df$y[i] == 1) | (df$z[i] == 1)){
    df$new[i] <- 1
  }
  else{
    df$new[i] <- 0
  }
}

We could even shorten it to, converting the logical to numeric:

for (i in 1:nrow(df)){
  df$new[i] <- +((df$x[i] == 1) | (df$y[i] == 1) | (df$z[i] == 1))
}

Output:

df
   x y z new
1  1 3 3   1
2  3 1 1   1
3  1 1 1   1
4  2 1 1   1
5  1 2 1   1
6  3 2 2   0
7  3 2 1   1
8  2 2 1   1
9  2 3 2   0
10 3 1 2   1