[R] Sum data according to date in sequence

[Christopher W. Ryan]

date appears to be a character variable, and R is treating it as such.

str(dt1)

might give you some insight.  Or the dplyr equivalent

glimpse(dt1)

I think R did what you asked, but if you want to be able to order
records by date, in temporal order, you need to tell R that it is a date:

library(dplyr)
sums <- dt1 %>%
    mutate(realDate = as.Date(date, format = "%m/%d/%Y") %>%
    group_by(realDate) %>%
    summarise(EnergykWh = sum(EnergykWh))


--Chris Ryan


roslinazairimah zakaria wrote:
> Dear all,
> 
> I have this set of data. I would like to sum the EnergykWh according date
> sequences.
> 
>> head(dt1,20)                   StationName      date  time EnergykWh
> 1  PALO ALTO CA / CAMBRIDGE #1 1/14/2016 12:09  4.680496
> 2  PALO ALTO CA / CAMBRIDGE #1 1/14/2016 19:50  6.272414
> 3  PALO ALTO CA / CAMBRIDGE #1 1/14/2016 20:22  1.032782
> 4  PALO ALTO CA / CAMBRIDGE #1 1/15/2016  8:25 11.004884
> 5  PALO ALTO CA / CAMBRIDGE #1 1/15/2016 14:23 10.096824
> 6  PALO ALTO CA / CAMBRIDGE #1 1/15/2016 18:17  6.658797
> 7  PALO ALTO CA / CAMBRIDGE #1 1/15/2016 21:46  4.808874
> 8  PALO ALTO CA / CAMBRIDGE #1 1/16/2016 10:19  1.469384
> 9  PALO ALTO CA / CAMBRIDGE #1 1/16/2016 12:12  2.996239
> 10 PALO ALTO CA / CAMBRIDGE #1 1/16/2016 14:12  0.303222
> 11 PALO ALTO CA / CAMBRIDGE #1 1/16/2016 16:22  4.988339
> 12 PALO ALTO CA / CAMBRIDGE #1 1/16/2016 19:16  8.131804
> 13 PALO ALTO CA / CAMBRIDGE #1 1/16/2016 19:19  0.117156
> 14 PALO ALTO CA / CAMBRIDGE #1 1/16/2016 20:24  3.285669
> 15 PALO ALTO CA / CAMBRIDGE #1 1/17/2016  9:54  1.175608
> 16 PALO ALTO CA / CAMBRIDGE #1 1/17/2016 12:16  3.677487
> 17 PALO ALTO CA / CAMBRIDGE #1 1/17/2016 13:53  1.068393
> 18 PALO ALTO CA / CAMBRIDGE #1 1/17/2016 19:03  8.820755
> 19 PALO ALTO CA / CAMBRIDGE #1 1/17/2016 22:00  8.138583
> 20 PALO ALTO CA / CAMBRIDGE #1 1/18/2016  8:58  9.057500
> 
> I have tried this:
> library(dplyr)
> sums <- dt1 %>%
>   group_by(date) %>%
>   summarise(EnergykWh = sum(EnergykWh))
> 
> head(sums,20)
> 
> The date is not by daily sequence but by year sequence.
> 
>> head(sums,20)# A tibble: 20 × 2
>    date      EnergykWh
>    <chr>         <dbl> 1 1/1/2017     25.3   2 1/1/2018     61.0   3
> 1/1/2019      0.627 4 1/1/2020     10.7   5 1/10/2017    69.4   6
> 1/10/2018    54.5   7 1/10/2019    49.1   8 1/10/2020    45.9   9
> 1/11/2017    73.9  10 1/11/2018    53.3  11 1/11/2019    93.5  12
> 1/11/2020    66.7  13 1/12/2017    78.6  14 1/12/2018    42.2  15
> 1/12/2019    22.7  16 1/12/2020    80.9  17 1/13/2017    85.6  18
> 1/13/2018    46.4  19 1/13/2019    40.0  20 1/13/2020   121.
> 
> 
> 
> Thank you very much for any help given.
> 
>