replace multiple values using ifelse

September 27, 2022

Based on the code and data below how can I replace values in the date column with new values using ifelse.

Error:

Warning message:
Problem while computing `date = ifelse(...)`.
ℹ longer object length is not a multiple of shorter object length

Data and code:

df = structure(list(id = c(1, 2, 3, 4, 5, 6, 7, 8), date = c("1/0/2000", 
"1/0/2005", "1/0/2005", "1/0/2005", "1/0/2005", "1/0/2005", "1/0/2005", 
"1/0/2005")), class = "data.frame", row.names = c(NA, -8L))

desired = structure(list(id = c(1, 2, 3, 4, 5, 6, 7, 8), date = c("01/01/2000", 
"01/01/2005", "01/01/2005", "01/01/2005", "01/01/2005", "01/01/2005", "01/01/2005", 
"01/01/2005")), class = "data.frame", row.names = c(NA, -8L))

df = df%>% mutate(date = ifelse(date == c("1/0/2000", "1/0/2005"), 
                                                   c("01/01/2000", "01/01/2005"), 
                                                   date)) # works if I run ifelse twice once for `1/0/2000` and once for `1/0/2005` without c()

>Solution :

You could use case_when instead of ifelse

df %>% mutate(date = case_when(date == "1/0/2000" ~ "01/01/2000", 
                               date == '1/0/2005' ~ "01/01/2005", 
                               TRUE ~ date))
#>   id       date
#> 1  1 01/01/2000
#> 2  2 01/01/2005
#> 3  3 01/01/2005
#> 4  4 01/01/2005
#> 5  5 01/01/2005
#> 6  6 01/01/2005
#> 7  7 01/01/2005
#> 8  8 01/01/2005