如何使用另一列中的值和条件填充列

Question

I have values in column "WT" and but some of the values need to be corrected by subtracting 0.01. I want to fill a new column "FinalWT" in my dataframe(df) with corrected values where Office is "1" and the equal values where Office is "2".

what I have:

Office  WT        
1       0.014   
2       0.456     
2       0.005     
1       0.051     

What I want to accomplish

Office  WT        FinalWT
1       0.014     0.004
2       0.456     0.456
2       0.005     0.005
1       0.051     0.041

Any help is greatly appreciated. Thanks!

Answer 1

We can multiply 0.01 with logical expression so that the output would be 0.01 for TRUE and 0 otherwisee and subtract from 'WT'

library(dplyr)
df1 %>%
      mutate(FinalWT = WT - 0.01 * (Office == 1))
#  Office    WT FinalWT
#1      1 0.014   0.004
#2      2 0.456   0.456
#3      2 0.005   0.005
#4      1 0.051   0.041

---

Or in base r

df1$FinalWT  <- with(df1, WT - 0.01 * (Office == 1))

data

df1 <- structure(list(Office = c(1L, 2L, 2L, 1L), WT = c(0.014, 0.456, 
0.005, 0.051)), class = "data.frame", row.names = c(NA, -4L))