How to sort the month_year column

Question

i am trying show Mar '21 as first and then go chronologically down from there

     emp.data <- data.frame(
  emp_id = c (1:12), 
  emp_name = c("Rick","Dan","Michelle","Ryan","Gary","aa","bb","cc","dd","ee","qq","ww"),
  m_year =c("Dec-2020", "Nov-2020", "Oct-2020", "Sep-2020", "Aug-2020", 
                "Jul-2020", "Jun-2020", "May-2020", "Apr-2020", "Mar-2021", "Feb-2021", 
                "Jan-2021")
)

i tried to sort the variable but still i am not getting the expected order

emp.data$m_year = emp.data$m_year[order(as.yearmon(emp.data$m_year, "%b-%Y"), decreasing = TRUE)]

G. Grothendieck · Accepted Answer · 2022-01-04T14:30:33.273

1

Convert to yearmon class in which case they sort chronologically. At the end we convert back to character. Omit the last leg of the pipeline if leaving it as yearmon is ok.

library(zoo)

x |>
  as.yearmon("%b-%Y") |>
  sort(decreasing = TRUE) |>
  format("%b-%Y")
##  [1] "Mar-2021" "Feb-2021" "Jan-2021" "Dec-2020" "Nov-2020" "Oct-2020"
##  [7] "Sep-2020" "Aug-2020" "Jul-2020" "Jun-2020" "May-2020" "Apr-2020"

Alternately write it like this:

format(sort(as.yearmon(x, "%b-%Y"), decreasing = TRUE), "%b-%Y")

or like this:

x[order(as.yearmon(x, "%b-%Y"), decreasing = TRUE)]

edited Jan 04 '22 at 14:30

answered Jan 04 '22 at 14:11

G. Grothendieck

254,981
17
203
341

Thanks its working fine – Nazima Jan 04 '22 at 14:34
with the help of u r code i can sort m_year column but based on that other columns are not sorting kindly check the sample data @G. Grothendieck – Nazima Jan 06 '22 at 06:02
Try this: `emp.data[order(as.yearmon(emp.data$m_year, "%b-%Y"), decreasing = TRUE), ]` – G. Grothendieck Jan 06 '22 at 11:56

How to sort the month_year column

1 Answers1