[R] Split a DF on Date column for each single year

[Ek Esawi]

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 using 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 using 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
> >
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> --
> Sent from my phone. Please excuse my brevity.