# [R] Something simple not working in group_by

Eric Berger er|cjberger @end|ng |rom gm@||@com
Tue Jul 10 09:48:13 CEST 2018

```Hi Sumit,
I was not able to reproduce this problem.
I tried it in both R 3.5.1 and R 3.4.4.
Both gave the expected output (which differs from yours.)

Eric

On Tue, Jul 10, 2018 at 1:32 AM, Bert Gunter <bgunter.4567 using gmail.com> wrote:

> Dunno.
>
> But if I understand correctly, here's a base R way to do it:
>
>
> > m\$total <- with(m,ave(score,id,FUN = cumsum))
> > m
>   id score total
> 1  1     6     6
> 2  1     6    12
> 3  2     6     6
> 4  2     3     9
> 5  3     3     3
> 6  3     3     6
>
> Cheers,
> Bert
>
>
>
>
> Bert Gunter
>
> "The trouble with having an open mind is that people keep coming along and
> sticking things into it."
> -- Opus (aka Berkeley Breathed in his "Bloom County" comic strip )
>
> On Mon, Jul 9, 2018 at 2:35 PM, Sumitrajit Dhar <s-dhar using northwestern.edu>
> wrote:
>
> > Hi Folks,
> >
> > I am trying to get a group_by cumsum using:
> >
> > R version 3.5.0 (2018-04-23) -- "Joy in Playing"
> > Copyright (C) 2018 The R Foundation for Statistical Computing
> > Platform: x86_64-apple-darwin15.6.0 (64-bit)
> >
> > Here is an example of a simple construct that is not working.
> >
> > m <- data.frame( id = rep(1:3, each=2), score = rep(c(6,3), each=3) )
> >
> > m %>% group_by(id) %>% mutate(total = cumsum(score))
> >
> > My output:
> >
> > # A tibble: 6 x 3
> > # Groups:   id [3]
> >      id score total
> >   <int> <dbl> <dbl>
> > 1     1     6     6
> > 2     1     6    12
> > 3     2     6    18
> > 4     2     3    21
> > 5     3     3    24
> > 6     3     3    27
> >
> > What am I missing? Thanks in advance.
> >
> > Regards,
> > Sumit
> >
> >
> > ______________________________________________
> > R-help using r-project.org mailing list -- To UNSUBSCRIBE and more, see
> > https://stat.ethz.ch/mailman/listinfo/r-help
> > posting-guide.html
> > and provide commented, minimal, self-contained, reproducible code.
> >
> >
>
>         [[alternative HTML version deleted]]
>
> ______________________________________________
> R-help using r-project.org mailing list -- To UNSUBSCRIBE and more, see
> https://stat.ethz.ch/mailman/listinfo/r-help