Quarter Conversion using casewhen - r

Question

I am trying to create a function so I convert the month values to quarters using the case when function.
Then I want to leverage mutate() to create a new variable Qtr and determine how many observations I see in each quarter.
convert_to_qtr <- function(Month) {
case_when(
Month == "Jan" ~ "Q1",
Month == "Feb" ~ "Q1",
Month == "Mar" ~ "Q1",
Month == "Apr" ~ "Q2",
Month == "May" ~ "Q2",
Month == "Jun" ~ "Q2",
Month == "Jul" ~ "Q3",
Month == "Aug" ~ "Q3",
Month == "Sep" ~ "Q3",
Month == "Oct" ~ "Q4",
Month == "Nov" ~ "Q4",
Month == "Dec" ~ "Q4"
)
}
example_months <- c("Jan", "Mar", "May", "May", "Aug", "Nov", "Nov", "Dec")
convert_to_qtr(example_months)
df %>%
mutate(Qtr = convert_to_qtr(Month)) %>%
group_by(Qtr) %>%
count(Qtr)
However I am not getting the same answer as my professor in his drop down so I am not sure if I am doing something wrong in my r coding.
He sees the numbers 161,071 85,588 100,227 142,651
I am not getting that, I see 152174 165778 205615 174592

Answer 1

You could write the function as below:
convert_to_qtr <- function(Month){
setNames(paste0("Q", rep(1:4,each=3)), month.abb)[Month]
}
df %>%
mutate(Qtr = convert_to_qtr(Month)) %>%
count(Qtr)
Qtr n
1 Q1 29
2 Q2 24
3 Q3 26
4 Q4 21