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<p>Sudhir,<br>
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.</p>
<p>I guess what you're looking for is:</p>
<p>dt[, my_date := as.Date(paste(1, my_date), format = "%d %b'%Y")]<br>
month_seq <- seq("2006-04-01", "2014-08-01", "month")<br>
dt_month <- data.table(month_int=1:length(month_seq),
month_seq=month_seq)<br>
setkey(dt, my_date)<br>
setkey(dt_month, month_seq)<br>
dt[dt_month, my_date_int := month_int]<br>
</p>
<p>--Mel.<br>
</p>
<br>
<div class="moz-cite-prefix">On 12/7/2016 7:14 PM, jim holtman
wrote:<br>
</div>
<blockquote type="cite"
cite="mid:CAAxdm-6Bq0EV50qRnGONPs1NLkGGF_mdLivg5+K4YpdCWJicXw@mail.gmail.com">
<div dir="ltr">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.</div>
<div class="gmail_extra"><br clear="all">
<div>
<div class="gmail_signature" data-smartmail="gmail_signature"><br>
Jim Holtman<br>
Data Munger Guru<br>
<br>
What is the problem that you are trying to solve?<br>
Tell me what you want to do, not how you want to do it.</div>
</div>
<br>
<div class="gmail_quote">On Tue, Dec 6, 2016 at 1:34 PM,
kbsudhir <span dir="ltr"><<a
href="mailto:kbsudhir@gmail.com" target="_blank"
moz-do-not-send="true">kbsudhir@gmail.com</a>></span>
wrote:<br>
<blockquote class="gmail_quote" style="margin:0 0 0
.8ex;border-left:1px #ccc solid;padding-left:1ex">Hi All,<br>
<br>
I am a beginner in R.<br>
<br>
I have a period of dates in my data set starting 10th
April'2006 till 31st<br>
Aug'2016. Its a period of 125 months. I want to sequentially
identify each<br>
month with a number starting "1" in a new corresponding
column Ex<br>
"Month_Identifier". Ex<br>
Apr'2006 - 1<br>
May'2006 - 2 ........ Aug'2016 - 125<br>
<br>
Also, the datatype of the column where date is available is
a factor.<br>
<br>
Requesting guidance on how to achieve this.<br>
<br>
Regards<br>
Sudhir<br>
<br>
<br>
<br>
--<br>
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