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

[Jeff Newmiller]

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.