Is this what you are after? library(tidyverse)
library(lubridate) input <- structure(list(StationName = c("PALO ALTO CA / CAMBRIDGE #1", "PALO ALTO CA / CAMBRIDGE #1", "PALO ALTO CA / CAMBRIDGE #1", "PALO ALTO CA / CAMBRIDGE #1", "PALO ALTO CA / CAMBRIDGE #1", "PALO ALTO CA / CAMBRIDGE #1", "PALO ALTO CA / CAMBRIDGE #1", "PALO ALTO CA / CAMBRIDGE #1", "PALO ALTO CA / CAMBRIDGE #1", "PALO ALTO CA / CAMBRIDGE #1", "PALO ALTO CA / CAMBRIDGE #1", "PALO ALTO CA / CAMBRIDGE #1", "PALO ALTO CA / CAMBRIDGE #1", "PALO ALTO CA / CAMBRIDGE #1", "PALO ALTO CA / CAMBRIDGE #1", "PALO ALTO CA / CAMBRIDGE #1", "PALO ALTO CA / CAMBRIDGE #1", "PALO ALTO CA / CAMBRIDGE #1", "PALO ALTO CA / CAMBRIDGE #1", "PALO ALTO CA / CAMBRIDGE #1"), date = c("1/14/2016", "1/14/2016", "1/14/2016", "1/15/2016", "1/15/2016", "1/15/2016", "1/15/2016", "1/16/2016", "1/16/2016", "1/16/2016", "1/16/2016", "1/16/2016", "1/16/2016", "1/16/2016", "1/17/2016", "1/17/2016", "1/17/2016", "1/17/2016", "1/17/2016", "1/18/2016"), time = c("12:09", "19:50", "20:22", "8:25", "14:23", "18:17", "21:46", "10:19", "12:12", "14:12", "16:22", "19:16", "19:19", "20:24", "9:54", "12:16", "13:53", "19:03", "22:00", "8:58"), EnergykWh = c(4.680496, 6.272414, 1.032782, 11.004884, 10.096824, 6.658797, 4.808874, 1.469384, 2.996239, 0.303222, 4.988339, 8.131804, 0.117156, 3.285669, 1.175608, 3.677487, 1.068393, 8.820755, 8.138583, 9.0575)), row.names = c(NA, 20L), class = "data.frame") # convert date from character to Date byDate <- input |> mutate(newdate = mdy(date)) |> group_by(newdate) |> summarise(total = sum(EnergykWh)) byDate ## # A tibble: 5 × 2 ## newdate total ## <date> <dbl> ## 1 2016-01-14 12.0 ## 2 2016-01-15 32.6 ## 3 2016-01-16 21.3 ## 4 2016-01-17 22.9 ## 5 2016-01-18 9.06 Thanks Jim Holtman *Data Munger Guru* *What is the problem that you are trying to solve?Tell me what you want to do, not how you want to do it.* On Fri, Nov 3, 2023 at 2:51 AM roslinazairimah zakaria <roslina...@gmail.com> wrote: > Hi, > I tried this: > # extract date from the time stamp > dt1 <- cbind(as.Date(dt$EndDate, format="%m/%d/%Y"), dt$EnergykWh) > head(dt1) > colnames(dt1) <- c("date", "EnergykWh") > and > my dt1 becomes these, the dates are replace by numbers. > > dt1 <- cbind(as.Date(dt$EndDate, format="%m/%d/%Y"), dt$EnergykWh) > dput(head(dt1)) > colnames(dt1) <- c("date", "EnergykWh") > dput(head(dt1)) > > > > dput(head(dt1))structure(c(16814, 16814, 16814, 16815, 16815, 16815, > 4.680496, > 6.272414, 1.032782, 11.004884, 10.096824, 6.658797), dim = c(6L, > 2L), dimnames = list(NULL, c("date", "EnergykWh"))) > > Then I tried this: > library(dplyr) > dt1 %>% > group_by(date) %>% > summarise(EnergykWh.sum = sum(EnergykWh)) > and got this errors > > dt1 %>%+ group_by(date) %>%+ summarise(EnergykWh.sum = > sum(EnergykWh))Error in UseMethod("group_by") : > no applicable method for 'group_by' applied to an object of class > "c('matrix', 'array', 'double', 'numeric')" > > > > On Fri, Nov 3, 2023 at 7:23 AM roslinazairimah zakaria < > roslina...@gmail.com> > 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. > > > > > > -- > > *Roslinazairimah Zakaria* > > *Tel: +609-5492370; Fax. No.+609-5492766* > > > > *Email: roslinazairi...@ump.edu.my <roslinazairi...@ump.edu.my>; > > roslina...@gmail.com <roslina...@gmail.com>* > > Faculty of Industrial Sciences & Technology > > University Malaysia Pahang > > Lebuhraya Tun Razak, 26300 Gambang, Pahang, Malaysia > > > > > -- > *Roslinazairimah Zakaria* > *Tel: +609-5492370; Fax. No.+609-5492766* > > *Email: roslinazairi...@ump.edu.my <roslinazairi...@ump.edu.my>; > roslina...@gmail.com <roslina...@gmail.com>* > Faculty of Industrial Sciences & Technology > University Malaysia Pahang > Lebuhraya Tun Razak, 26300 Gambang, Pahang, Malaysia > > [[alternative HTML version deleted]] > > ______________________________________________ > R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see > https://stat.ethz.ch/mailman/listinfo/r-help > PLEASE do read the posting guide > http://www.R-project.org/posting-guide.html > and provide commented, minimal, self-contained, reproducible code. > [[alternative HTML version deleted]] ______________________________________________ R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.