similar to: proposed change to [.POSIXct

Hi all; I've already send a similar e-mail to the list and Prof. Brian Ripley answered me but my doubts remain unresolved. Thanks for the clarification, but perhaps I wasn't clear enough in posting my questions. I've got a postgres database which I read into R. The first column is Timestamp with timezone, and my data are already in UTC format. An 'printed' extract of R

Full_Name: Bo Zhou Version: 2.6.1 (2007-11-26) OS: Windows XP Submission from: (NULL) (207.237.54.242) Hi, I found an arithmetic problem when I'm doing something with POSIXct The code to reproduce it is as follows (This is the recommended way of finding out time zone difference on R News 2004-1 Page 32 URL http://cran.r-project.org/doc/Rnews/Rnews_2004-1.pdf) a=Sys.time()

Hello: What is the recommended method for retaining the tzone attributes when concatonating POSIXct objects? > (d1 <- ISOdate(1970,1,1)) # Sets the tzone attribute = GMT [1] "1970-01-01 12:00:00 GMT" > (d1.2 <- c(d1, d1)) # c(..) strips the tzone attribute, displays in the time zone of the operating system [1] "1970-01-01 04:00:00 PST" "1970-01-01

Although the documentation is somewhat sketchy, I() can be used to create objects of class AsIs: > I("a") [1] "a" attr(,"class") [1] "AsIs" "character" > I(4) [1] 4 attr(,"class") [1] "AsIs" "numeric" > I(4 + 0i) [1] 4+0i attr(,"class") [1] "AsIs" "complex" > This

Hi all, I'm having difficulty converting a 'dates' object to a POSIXct object: testDATES<-c(35947,35971,36004,36008,36053,36066) testDATES<-chron(dates=testDATES, format = c(dates = "m/d/y"), origin=c(month = 12, day = 30, year = 1899)) >[1] 06/01/98 06/25/98 07/28/98 08/01/98 09/15/98 09/28/98 > as.POSIXct(testDATES) [1] NA NA NA NA NA NA

How do I get a number representing a date from a POSIXct i.e. removing the time elements? -- View this message in context: http://n4.nabble.com/how-to-return-date-part-of-POSIXct-tp1598109p1598109.html Sent from the R help mailing list archive at Nabble.com.

Hi all, I noticed that `range.default()` has a nice `finite = TRUE` argument, but it doesn't actually apply to Date or POSIXct due to how `is.numeric()` works. ``` x <- .Date(c(0, Inf, 1, 2, Inf)) x #> [1] "1970-01-01" "Inf" "1970-01-02" "1970-01-03" "Inf" # Darn! range(x, finite = TRUE) #> [1] "1970-01-01"

I am using R-1.7.0 and have some data which consist of one vector of numbers and a second corresponding vector of dates belonging to the POSIXct class. I would like to plot the numbers against the dates. What is the best way to do this? It almost works to just call `plot.' However if I do this while using the `ylab' parameter I get a warning message: parameter "ylab"

Hi All, I think there may be some possible confusion about what allowsInf would be reporting (or maybe its just me :) ) if we did this. Consider a class "myclass", S3, for starters, with setMethod("allowsInf", "myclass", function(obj) FALSE) Then, what would myclassthing <- structure(1.5, class = "mything") myclassthing[1] <- Inf do. Assumely it

Greetings - I'm battling POSIXct, as per the code below. My input is actually an XL file, but the weird results below correctly model what I am seeing in my program. Before I punt and use lubridate or timeDate, could anyone please help me understand why POSIXct forces my variable back to GMT? I suspect that I'm not properly coding the tzone value, but it does not throw an

> x<-as.POSIXct("1970-1-1", tz="UTC")-.5 > y<-as.POSIXct("1970-1-1", tz="UTC")+.5 > x==y [1] FALSE # of course but x and y "appear" to be the same when formatted, even with extra precision: > format(x, format="%Y-%m-%d %H:%M:%OS2") [1] "1970-01-01 00:00:00.50" > format(y, format="%Y-%m-%d

A tiny nit-pick: Seems to me that end date = NA would mean the event has not yet ended, whilst Inf would mean that the event is known to never terminate, ie: an eternal fact, or physical law. On Fri, Apr 28, 2023 at 10:12?AM Davis Vaughan via R-devel < r-devel at r-project.org> wrote: > Hi all, > > I noticed that `range.default()` has a nice `finite = TRUE` argument, > but it

I am trying to use POSIX datetime objects rather than chron datetime objects but am having difficulty with POSIX in a time series. My question: Once a POSIXct vector is bound to a time series, is there a function to convert back to POSIXct? The following code demonstrates what I am trying to do. > ts(as.POSIXct(strptime(tmp,"%m/%d/%Y %H:%M:%S")),freq=1440) Time Series: Start =

I am finding that axis.POSIXct uses the local timezone for deciding where to put tic marks, even if the data being plotted are in another time zone. The solution is to use attr() to copy from the 'x' (provided as an argument) to the 'z' (used for the 'at' locations). I have pasted my proposed solution in section 1 below (as a diff). Then, in section 2, I'll put some

R 3.5.0 Is it intended that the Date method of as.POSIXct does not respect the tz parameter? I suggest changing as.POSIXct.Date to this: function (x, tz = "", ...) .POSIXct(unclass(x) * 86400, tz = tz) Currently, the best workaround seems to be using the character method if one doesn't want the default timezone (which is often an annoying DST timezone). This came up on

I have some data that was created for import into a Lotus 1-2-3 spreadsheet and on of the columns is time. The time is akin to Julian were the value 1 is mapped "01-Jan-00 12:00:00 AM" in Lotus 1-2-3. Is there a function in an R package that can convert this numeric vector to a POSIXct vector? With best wishes and kind regards I am Sincerely, Corey A. Moffet Instructor Department

Can someone help me understand the following behavior of "[<-" ? If I define a simple class based on a matrix, the [<- operation only inserts into the first column: > x <- matrix(rnorm(10),nrow=5,ncol=2) > class(x) <- "foo" > "[<-.foo" <- function(x, i, j, value) { + if(missing(i)) i <- 1:nrow(x) + if(missing(j)) j <-

I am trying to do ephemeris calculations in R, which involves calculating an elapsed time. As illustrated below, difftime seems to have problems with my method, since the fractional day is sometimes the correct 0.5 and sometimes the incorrect 0.46. I am doing this on with R-2.6.1 on a powerpc-apple-darwin8.10.1 system. I get the same results for as.POSIXlt() instead of as.POSIXct(), but the

Hello, I have strings with date-/time-data from a logfile. For a sort-by-time (and other time-related analysis) I need something to convert the times to the Unix-epoche-time (better also with parts of seconds). Is there something that does that job (or a similar conversion) in R? TIA, Oliver Bandel

Hi, I have some dates that are giving me a problem, in general the dates look like this: free.dates[60:61] [1] "2009-05-21 23:45:00 GMT" "2009-05-22 00:00:00 GMT" but for some reason, when taken "alone", they look like this: free.dates[60] [1] "2009-05-21 23:45:00 GMT" free.dates[61] [1] "2009-05-22 GMT" # the time component is gone, and