Sequentially summing values in a column with value above

[JeffF]

This is probably simple, but I cannot figure it out. In R, I would like to take adjacent values and add to the sum of the values in another column. In Excel it would be where the value is added to the cell value along with the value of the cell above except for very first value because there is no value above. Better explained is this table.

value	value_summed
28	28
41	69
71	140
92	232
39	271
64	335
25	360
21	381
17	398
59	457
38	495
97	592

How do I do this?

Thanks,
Jeff

[jrkrideau]

Is this what you want?

dat1 <- tibble::tribble(
  ~value, ~value_summed,
     28L,           28L,
     41L,           69L,
     71L,          140L,
     92L,          232L,
     39L,          271L,
     64L,          335L,
     25L,          360L,
     21L,          381L,
     17L,          398L,
     59L,          457L,
     38L,          495L,
     97L,          592L
  )

cumsum(dat1$value)

[JeffF]

Yes. Using your suggested cumsum, here is how I did it.

value <- c(28, 41, 71, 92, 39, 64, 25, 21, 17, 59, 38, 97)
dat1 <- data.frame(value)
dat1$value_summed <- cumsum(dat1$value)
dat1
#>    value value_summed
#> 1     28           28
#> 2     41           69
#> 3     71          140
#> 4     92          232
#> 5     39          271
#> 6     64          335
#> 7     25          360
#> 8     21          381
#> 9     17          398
#> 10    59          457
#> 11    38          495
#> 12    97          592

Pretty simple. Glad I asked.

Thanks,
Jeff