Hello, I forgot to add that I don't find your
unlist(agg[2], use.names = FALSE) the best way, `[` extracts a sub-data.frame, use `[[` instead. unlist(agg[[2]], use.names = FALSE) It may not make a difference, followed by unlist the results might be the same but it is conceptually better to extract the column, to use `[[`. See the difference between the two: str(agg[2]) str(agg[[2]]) Hope this helps, Rui Barradas Rui Barradas <[email protected]> escreveu (segunda, 10/08/2026 à(s) 11:51): > > Hello, > > The problem is that the first aggregate's second column is a list and > the second aggregate's second column is a matrix. > In the code below I have complicated it a bit so that the intermediate > results are created and examined. > > mydf <- data.frame( > Data=seq(as.POSIXct("2003-01-01", format = "%Y-%m-%d", > tz="Etc/GMT-1"), as.POSIXct("2023-12-31", format = "%Y-%m-%d", > tz="Etc/GMT-1"), by="1 day"), > daily_mean = round(runif(7670, 0, 2), digits=2)) > > agg <- aggregate(daily_mean ~ as.integer(format(mydf$Data, "%Y")), > data=mydf, cumsum) > > mydf$yearly_sum <- unlist(agg[2], use.names = FALSE) > > > mydf1 <- data.frame( > Data=seq(as.POSIXct("2003-01-01", format = "%Y-%m-%d", > tz="Etc/GMT-1"), as.POSIXct("2023-12-31", format = "%Y-%m-%d", > tz="Etc/GMT-1"), by="1 day"), > daily_mean = round(runif(7670, 0, 2), digits=2)) > dim(mydf1) > #> [1] 7670 2 > > # this removes 5 rows from mydf1 > i <- format(mydf1$Data, "%m-%d") != "02-29" > mydf1 <- mydf1[i, ] > dim(mydf1) > #> [1] 7665 2 > > agg2 <- aggregate(daily_mean ~ as.integer(format(mydf1$Data, "%Y")), > data=mydf1, cumsum) > mydf1$yearly_sum <- unlist(agg2[2], use.names = FALSE) > > > > Now see what is in agg and in agg2. > > > class(agg$daily_mean) > #> [1] "list" > # returns FALSE, 5 list members have length 366 > all(lengths(agg$daily_mean) == 365) > #> [1] FALSE > lengths(agg$daily_mean) > #> [1] 365 366 365 365 365 366 365 365 365 366 365 365 365 366 365 > 365 365 366 365 > #> [20] 365 365 > > class(agg2$daily_mean) > #> [1] "matrix" "array" > ncol(agg2$daily_mean) == 365 > #> [1] TRUE > > > agg2's second column is a matrix where each row represents the year's > cumulative sums. R stores matrices in column-first order so you have > to transpose the matrix and then remove the dim attribute (for > instance, with `c`), not `unlist` it. > > > # after running the agg2 <- aggregate(...) above, run > mydf1$yearly_sum <- c(t(agg2$daily_mean)) > > > Hope this helps, > > Rui Barradas > > > Stefano Sofia via R-help <[email protected]> escreveu (segunda, > 10/08/2026 à(s) 11:07): > > > > Dear R-list users, > > > > I've got problems to use the function aggregate. > > > > > > Here there is an example: > > > > > > mydf <- data.frame(Data=seq(as.POSIXct("2003-01-01", format = "%Y-%m-%d", > > tz="Etc/GMT-1"), as.POSIXct("2023-12-31", format = "%Y-%m-%d", > > tz="Etc/GMT-1"), by="1 day"), daily_mean = round(runif(7670, 0, 2), > > digits=2)) > > > > mydf$yearly_sum <- unlist(aggregate(daily_mean~as.integer(format(mydf$Data, > > "%Y")), data=mydf, cumsum)[2], use.names = FALSE) > > > > > > The column "yearly_sum" is the sum of the column "daily_mean" with a reset > > at the beginning of each year. > > > > If for my analysis I want to remove the 29th of February, "yearly_sum" does > > not work anymore: > > > > > > mydf1 <- data.frame(Data=seq(as.POSIXct("2003-01-01", format = "%Y-%m-%d", > > tz="Etc/GMT-1"), as.POSIXct("2023-12-31", format = "%Y-%m-%d", > > tz="Etc/GMT-1"), by="1 day"), daily_mean = round(runif(7670, 0, 2), > > digits=2)) > > > > mydf1 <- mydf1[format(mydf1$Data, "%m-%d") != "02-29", ] > > > > mydf1$yearly_sum <- > > unlist(aggregate(daily_mean~as.integer(format(mydf1$Data, "%Y")), > > data=mydf1, cumsum)[2], use.names = FALSE) > > > > > > In this case the column "yearly_sum" does not sum the values, and honestly > > I do not understand what is happening. Why? > > > > Could somebody help me? I already spent a big amount of hours with no > > success. > > > > > > Thank you for your attention and you help > > > > Stefano > > > > > > > > > > (oo) > > --oOO--( )--OOo-------------------------------------- > > Stefano Sofia MSc, PhD > > Civil Protection Department - Marche Region - Italy > > Meteo Section > > Snow Section > > Via Colle Ameno 5 > > 60126 Torrette di Ancona, Ancona (AN) > > Uff: +39 071 806 7743 > > E-mail: [email protected] > > ---Oo---------oO---------------------------------------- > > > > ________________________________ > > > > AVVISO IMPORTANTE: Questo messaggio di posta elettronica può contenere > > informazioni confidenziali, pertanto è destinato solo a persone autorizzate > > alla ricezione. I messaggi di posta elettronica per i client di Regione > > Marche possono contenere informazioni confidenziali e con privilegi legali. > > Se non si è il destinatario specificato, non leggere, copiare, inoltrare o > > archiviare questo messaggio. Se si è ricevuto questo messaggio per errore, > > inoltrarlo al mittente ed eliminarlo completamente dal sistema del proprio > > computer. Ai sensi dell'art. Ai sensi dell'art. 2.4 dell'allegato 1 alla > > DGR n. 74/2021, si segnala che, in caso di necessità ed urgenza, la > > risposta al presente messaggio di posta elettronica può essere visionata da > > persone estranee al destinatario. > > IMPORTANT NOTICE: This e-mail message is intended to be received only by > > persons entitled to receive the confidential information it may contain. > > E-mail messages to clients of Regione Marche may contain information that > > is confidential and legally privileged. Please do not read, copy, forward, > > or store this message unless you are an intended recipient of it. If you > > have received this message in error, please forward it to the sender and > > delete it completely from your computer system. > > > > [[alternative HTML version deleted]] > > > > ______________________________________________ > > [email protected] mailing list -- To UNSUBSCRIBE and more, see > > https://stat.ethz.ch/mailman/listinfo/r-help > > PLEASE do read the posting guide > > https://www.R-project.org/posting-guide.html > > and provide commented, minimal, self-contained, reproducible code. ______________________________________________ [email protected] mailing list -- To UNSUBSCRIBE and more, see https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide https://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
