I have just started to learn R and I am trying to create a new variable + using ifelse.
nlsy$ethnicity <- as.factor(ifelse(nlsy$race_ethnicity=="Black", "Black",
ifelse(nlsy$race_ethnicity=="Hispanic", "Hispanic",
ifelse(nlsy$race_ethnicity=="Non-Black / Non-Hispanic" & nlsy$race_ethnicity="White", "White", "Other"))))
Use case_when from the dplyr package here:
nlsy$ethnicity <- case_when(
nlsy$race_ethnicity == "Black" ~ "Black",
nlsy$race_ethnicity == "Hispanic" ~ "Hispanic",
nlsy$race_ethnicity == "Non-Black / Non-Hispanic" | nlsy$race_ethnicity == "White" ~ "White",
TRUE ~ "Other
)
Using case_when is often preferable to ifelse especially in the case where the latter involves many nested calls.
We could make this a bit more simpler with
library(dplyr)
nlsy <- nlsy %>%
mutate(ethnicity = replace(replace(race_ethnicity,
race_ethnicity == "Non-Black / Non-Hispanic", "White"),
!race_ethnicity %in% c("Black", "Hispanic", "White"), "Other"))
There is also a package called fmtr that is good for this situation. It has a value() function, which is similar to a SAS user-defined format. Here is how you use it:
library(fmtr)
# Define format
fmt <- value(condition(x == "Black", "Black"),
condition(x == "Hispanic", "Hispanic"),
condition(x == "Non-Black / Non-Hispanic" & x == "White", "White"),
condition(TRUE, "Other")
# Apply format
nlsy$ethnicity <- fapply(nlsy$race_ethnicity, fmt)
case_whenfromdplyrto avoid nestedifelsestatements, but it would also be good to see some sample data to better understand what you are trying to do here.nlsy$race_ethnicity="White", which actually should benlsy$race_ethnicity== "White". Also maybe the condition should be|(OR) rather than&(AND).