Message-ID: <CA+ZkTxv_0xWczcYqp0NNQ9r92YozFZDY_C3vRq9iNXHPx7wi2g@mail.gmail.com>
Date: 2019-03-16T06:39:21Z
From: Ek Esawi
Subject: Split a DF on Date column for each single year
In-Reply-To: <BF4206FE-112F-4EF0-852C-CAA62075CF74@dcn.davis.ca.us>
Thank you Jeff and Rainer. I will try Jeff's idea using the sub
string. function to extract the year and split on that.
Thanks again to both--EK
On Sat, Mar 16, 2019 at 1:52 AM Jeff Newmiller <jdnewmil at dcn.davis.ca.us> wrote:
>
> Couldn't you just use the substr function to pull the year out yourself to make the grouping column?
>
> On March 15, 2019 10:40:01 PM PDT, Ek Esawi <esawiek at gmail.com> wrote:
> >Hi All?
> >
> >I have a data frame with over 13000 rows and 4 columns. A mini data
> >frame is given at the bottom. I want to split the data frame into
> >lists each corresponds to single year which ranges from 1990 to 2018).
> >I wanted to use the split function, but it requires a vector of the
> >same length as MyDate which contains many multiples of each year.
> >Any help is highly appreciated.
> >
> >I want the following results:
> >List 1990
> >MyDate MyNo MyDes
> >1990
> >1990
> >1990
> >?...
> >List 2000
> >2000
> >2000
> >2000
> >?...
> >List 2001
> >2001
> >2001
> >2001
> >2001
> >?...
> >List 2018
> >2018
> >2018
> >2018
> >?...
> >
> >Sample data frame
> >
> >mydf <-
> >data.frame(MyDate=c("1990-01-01","1990-04-07","2000-04-05","2018-01-04"),MyNo=c(1,2,3,4),MyDes=c("AA","BB","CC","DD"))
> >
> >
> >EK
> >
> >______________________________________________
> >R-help at r-project.org mailing list -- To UNSUBSCRIBE and more, see
> >https://stat.ethz.ch/mailman/listinfo/r-help
> >PLEASE do read the posting guide
> >http://www.R-project.org/posting-guide.html
> >and provide commented, minimal, self-contained, reproducible code.
>
> --
> Sent from my phone. Please excuse my brevity.