Extract data for all days for last 30 days from R data frame

Question

I am totally new to R environment and I'm stuck at Date operations. The scenario is, I have a daily database of customer activity of a certain Store, and I need to extract last 30 months data starting from current date. In other words, suppose today is 18-NOV-2014, I need all the data from 18-OCT-2014 till today in a separate data-frame. To extract it, what kind of iteration logic should I write in R?

Please supply [a reproducible example](http://stackoverflow.com/questions/5963269/how-to-make-a-great-r-reproducible-example) including (a sample of) your data and any code you've already tried. — Thomas, Nov 18 '14 at 10:18

score 4 · Accepted Answer · answered Nov 18 '14 at 10:19

4

You don't need an iteration. What you could do is, assuming your data.frame is called X, and the date column, DATE, you could write:

X$DATE=as.Date(X$DATE, format='%d-%B-%Y')

the 'format' argument is to match your date format you specify in you question. Then, to get the lines you are interested in, something like:

X[X$DATE>=as.Date(today(),format='%d-%B-%Y')-30)]

which is all the lines that are after today - 30 days. Does this help at all?

answered Nov 18 '14 at 10:19

Nikos

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Yes @Nikos, that is the exact thing I needed! – sunitprasad1 Nov 18 '14 at 10:26
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@DavidArenburg it is an equivalent of Sys.Date() – sunitprasad1 Nov 18 '14 at 10:27
I don't have that function in R, do you? – David Arenburg Nov 18 '14 at 10:28
Apologies. David is right, sorry I had already loaded lubridate in my project. Sys.Date() is perhaps better (to use only base R). Thank you for mentioning it David. – Nikos Nov 18 '14 at 10:29
Yes, apologies from my side too. Thanks David. – sunitprasad1 Nov 18 '14 at 10:53

Extract data for all days for last 30 days from R data frame

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