Recoding a variable in R

[odeoyvind]

Hi! I have a time variable which is coded "0, 1, 2 , 3," I want to recode this variable to be "--1.5, -0.5, 0.5, 1.5"

data1 <- data %>%
mutate(time = replace(time, time == 0, - 1.5 )) %>%
mutate(time = replace(time, time == 1, - 0.5 )) %>%
mutate(time = replace(time, time == 2, 0.5 )) %>%
mutate(time = replace(time, time == 3, 1.5 ))

i tried the following function, recode(data$time, "0" = - 1.5, "1" = -0.5, "2" = 0.5, "3" = 1.5)

But none of the functions would cooperate. Does anyone have any tips?

[michaelbgarcia]

this looks like a good use case for dplyr::case_when

A general vectorised if-else — case_when

[startz]

While this is not at all general, for the specific case you have how about

data$time <- data$time - 1.5

[Equation]

If the pattern is that you want to subtract 1.5 from each observation, the following simple approach also works to achieve that.

library(tidyverse)

time <- tibble(
  time = c(0, 1, 2, 3)
)

time %>% 
  mutate(time = time - 1.5)

#> # A tibble: 4 × 1
#>    time
#>   <dbl>
#> 1  -1.5
#> 2  -0.5
#> 3   0.5
#> 4   1.5

[odeoyvind]

Thank you so much for all your answers. I ended up using the simple mutate() function which was proposed. But I'm going to take a look at the "case_when" function for future problems, im expecting them to not always be so elegant to solve.