Sudhir,
Read the documentation for R function `as.Date()`, e.g. you can
transform your factor column to a date column using `as.Date(my_date,
format = "%d%b'%Y")`, then order/sort on that column.
I guess what you're looking for is:
dt[, my_date := as.Date(paste(1, my_date), format = "%d %b'%Y")]
month_seq <- seq("2006-04-01", "2014-08-01", "month")
dt_month <- data.table(month_int=1:length(month_seq), month_seq=month_seq)
setkey(dt, my_date)
setkey(dt_month, month_seq)
dt[dt_month, my_date_int := month_int]
--Mel.
On 12/7/2016 7:14 PM, jim holtman wrote:
Please at least supply a sample of the data. Is there more than one
row per month, are there months missing, if so how to handle. You
left a lot unspecified. Guidance can be provided with data.
Jim Holtman
Data Munger Guru
What is the problem that you are trying to solve?
Tell me what you want to do, not how you want to do it.
On Tue, Dec 6, 2016 at 1:34 PM, kbsudhir <[email protected]
<mailto:[email protected]>> wrote:
Hi All,
I am a beginner in R.
I have a period of dates in my data set starting 10th April'2006
till 31st
Aug'2016. Its a period of 125 months. I want to sequentially
identify each
month with a number starting "1" in a new corresponding column Ex
"Month_Identifier". Ex
Apr'2006 - 1
May'2006 - 2 ........ Aug'2016 - 125
Also, the datatype of the column where date is available is a factor.
Requesting guidance on how to achieve this.
Regards
Sudhir
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