Something simple not working in group_by

On Jul 10, 2018, at 2:48 AM, Eric Berger <ericjberger at gmail.com> wrote:

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 at gmail.com <mailto:bgunter.4567 at gmail.com>> wrote:
Dunno.

But if I understand correctly, here's a base R way to do it:

(## using your m)

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 at northwestern.edu <mailto:s-dhar at 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

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