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 <esaw...@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@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. ______________________________________________ R-help@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.