Dear R-list members,
I have semi-hourly snowfall data.
I should sum the semi-hourly increments (only the positive ones, but this is not
described in my example) day by day, not from 00 to 24 but from 9 to 9.
I am able to use the diff function, create a list of days and use the function
aggregate, but it works only from 0 to 24. Any suggestion for an efficient way
to do it?
Here my code:
day_1 <- as.POSIXct("2020-02-19-00-00",
format="%Y-%m-%d-%H-%M", tz="Etc/GMT-1")
day_2 <- as.POSIXct("2020-02-24-12-00",
format="%Y-%m-%d-%H-%M", tz="Etc/GMT-1")
df1 <- data.frame(data_POSIX=seq(day_1, day_2, by="30 min"))
df1$hs <- rnorm(nrows(df1), 40, 10)
df1$diff[2:nrow(df1)] <- diff(df1$hs)
df1$day <- format(df$data_POSIX,"%y-%m-%d")
df2 <- aggregate(diff ~ day, df, sum)
Thank you for your help
Stefano
         (oo)
--oOO--( )--OOo----------------
Stefano Sofia PhD
Civil Protection - Marche Region
Meteo Section
Snow Section
Via del Colle Ameno 5
60126 Torrette di Ancona, Ancona
Uff: 071 806 7743
E-mail: stefano.sofia at regione.marche.it
---Oo---------oO----------------
________________________________
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Hi Stefano,
If you mean from 9am on one day to 9am on the following day, you can
do a trick. Simply subtract 9hrs from each timestamp and then you want
midnight to midnight for these adjusted times, which you can get using
the method you followed.
I googled and found that lubridate::hours() can be used to add or
subtract hours from a POSIXct.
library(lubridate)
day_1 <- as.POSIXct("2020-02-19-00-00",
format="%Y-%m-%d-%H-%M", tz="Etc/GMT-1")
day_2 <- as.POSIXct("2020-02-24-12-00",
format="%Y-%m-%d-%H-%M", tz="Etc/GMT-1")
df1 <- data.frame(data_POSIX=seq(day_1, day_2, by="30 min"))
df1$hs <- rnorm(nrow(df1), 40, 10)
df1$diff[2:nrow(df1)] <- diff(df1$hs)
df1$data_POSIXminus9 <- df1$data_POSIX - lubridate::hours(9)
df1$dayX <- format(df1$data_POSIXminus9,"%y-%m-%d")
df2X <- aggregate(diff ~ dayX, df1, sum)
df2X
HTH,
Eric
On Mon, Sep 21, 2020 at 5:30 PM Stefano Sofia
<stefano.sofia at regione.marche.it> wrote:>
> Dear R-list members,
> I have semi-hourly snowfall data.
> I should sum the semi-hourly increments (only the positive ones, but this
is not described in my example) day by day, not from 00 to 24 but from 9 to 9.
>
> I am able to use the diff function, create a list of days and use the
function aggregate, but it works only from 0 to 24. Any suggestion for an
efficient way to do it?
> Here my code:
> day_1 <- as.POSIXct("2020-02-19-00-00",
format="%Y-%m-%d-%H-%M", tz="Etc/GMT-1")
> day_2 <- as.POSIXct("2020-02-24-12-00",
format="%Y-%m-%d-%H-%M", tz="Etc/GMT-1")
> df1 <- data.frame(data_POSIX=seq(day_1, day_2, by="30 min"))
> df1$hs <- rnorm(nrows(df1), 40, 10)
> df1$diff[2:nrow(df1)] <- diff(df1$hs)
> df1$day <- format(df$data_POSIX,"%y-%m-%d")
> df2 <- aggregate(diff ~ day, df, sum)
>
> Thank you for your help
> Stefano
>
>          (oo)
> --oOO--( )--OOo----------------
> Stefano Sofia PhD
> Civil Protection - Marche Region
> Meteo Section
> Snow Section
> Via del Colle Ameno 5
> 60126 Torrette di Ancona, Ancona
> Uff: 071 806 7743
> E-mail: stefano.sofia at regione.marche.it
> ---Oo---------oO----------------
>
> ________________________________
>
> AVVISO IMPORTANTE: Questo messaggio di posta elettronica pu? contenere
informazioni confidenziali, pertanto ? 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 ?
il destinatario specificato, non leggere, copiare, inoltrare o archiviare questo
messaggio. Se si ? ricevuto questo messaggio per errore, inoltrarlo al mittente
ed eliminarlo completamente dal sistema del proprio computer. Ai sensi dell?art.
6 della DGR n. 1394/2008 si segnala che, in caso di necessit? ed urgenza, la
risposta al presente messaggio di posta elettronica pu? 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.
>
> --
> Questo messaggio  stato analizzato da Libra ESVA ed  risultato non infetto.
> This message was scanned by Libra ESVA and is believed to be clean.
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>
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>
> ______________________________________________
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> https://stat.ethz.ch/mailman/listinfo/r-help
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> and provide commented, minimal, self-contained, reproducible code.
The base R as.difftime function is perfectly usable to create this offset without pulling in lubridate. On September 21, 2020 8:06:51 AM PDT, Eric Berger <ericjberger at gmail.com> wrote:>Hi Stefano, >If you mean from 9am on one day to 9am on the following day, you can >do a trick. Simply subtract 9hrs from each timestamp and then you want >midnight to midnight for these adjusted times, which you can get using >the method you followed. > >I googled and found that lubridate::hours() can be used to add or >subtract hours from a POSIXct. > >library(lubridate) > >day_1 <- as.POSIXct("2020-02-19-00-00", format="%Y-%m-%d-%H-%M", >tz="Etc/GMT-1") >day_2 <- as.POSIXct("2020-02-24-12-00", format="%Y-%m-%d-%H-%M", >tz="Etc/GMT-1") >df1 <- data.frame(data_POSIX=seq(day_1, day_2, by="30 min")) >df1$hs <- rnorm(nrow(df1), 40, 10) >df1$diff[2:nrow(df1)] <- diff(df1$hs) > >df1$data_POSIXminus9 <- df1$data_POSIX - lubridate::hours(9) >df1$dayX <- format(df1$data_POSIXminus9,"%y-%m-%d") >df2X <- aggregate(diff ~ dayX, df1, sum) >df2X > >HTH, >Eric > >On Mon, Sep 21, 2020 at 5:30 PM Stefano Sofia ><stefano.sofia at regione.marche.it> wrote: >> >> Dear R-list members, >> I have semi-hourly snowfall data. >> I should sum the semi-hourly increments (only the positive ones, but >this is not described in my example) day by day, not from 00 to 24 but >from 9 to 9. >> >> I am able to use the diff function, create a list of days and use the >function aggregate, but it works only from 0 to 24. Any suggestion for >an efficient way to do it? >> Here my code: >> day_1 <- as.POSIXct("2020-02-19-00-00", format="%Y-%m-%d-%H-%M", >tz="Etc/GMT-1") >> day_2 <- as.POSIXct("2020-02-24-12-00", format="%Y-%m-%d-%H-%M", >tz="Etc/GMT-1") >> df1 <- data.frame(data_POSIX=seq(day_1, day_2, by="30 min")) >> df1$hs <- rnorm(nrows(df1), 40, 10) >> df1$diff[2:nrow(df1)] <- diff(df1$hs) >> df1$day <- format(df$data_POSIX,"%y-%m-%d") >> df2 <- aggregate(diff ~ day, df, sum) >> >> Thank you for your help >> Stefano >> >> (oo) >> --oOO--( )--OOo---------------- >> Stefano Sofia PhD >> Civil Protection - Marche Region >> Meteo Section >> Snow Section >> Via del Colle Ameno 5 >> 60126 Torrette di Ancona, Ancona >> Uff: 071 806 7743 >> E-mail: stefano.sofia at regione.marche.it >> ---Oo---------oO---------------- >> >> ________________________________ >> >> AVVISO IMPORTANTE: Questo messaggio di posta elettronica pu? >contenere informazioni confidenziali, pertanto ? 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 ? il destinatario specificato, non >leggere, copiare, inoltrare o archiviare questo messaggio. Se si ? >ricevuto questo messaggio per errore, inoltrarlo al mittente ed >eliminarlo completamente dal sistema del proprio computer. Ai sensi >dell?art. 6 della DGR n. 1394/2008 si segnala che, in caso di necessit? >ed urgenza, la risposta al presente messaggio di posta elettronica pu? >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. >> >> -- >> Questo messaggio stato analizzato da Libra ESVA ed risultato non >infetto. >> This message was scanned by Libra ESVA and is believed to be clean. >> >> >> [[alternative HTML version deleted]] >> >> ______________________________________________ >> R-help at 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. > >______________________________________________ >R-help at 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.-- Sent from my phone. Please excuse my brevity.