similar to: Date method of as.POSIXct does not respect tz

Dear All, what determines if a difference between POSIXct objects gets expressed in days or seconds? In the following example, it's sometimes seconds, sometimes days. as.POSIXct('2009-09-01') - as.POSIXct(NA) Time difference of NA secs c(as.POSIXct('2009-09-01'), as.POSIXct(NA)) - c(as.POSIXct('2009-09-01'), as.POSIXct('2009-08-31')) Time differences in

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

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()

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"

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

Dear R list, I noticed the following 'problem' when changing the format of dates created with seq.dates() (from the Chron library) using as.POSIXct() (R 1.8.0 on OSX 10.2.8): > datesTest<-seq.dates(from="10/01/1952", length=3, by="days"); > datesTest [1] 10/01/52 10/02/52 10/03/52 # Now changing the format to show year as 1952. >

Under platform i686-pc-linux-gnu arch i686 os linux-gnu system i686, linux-gnu status major 1 minor 6.1 year 2002 month 11 day 01 language R > x <- strptime(c('10/10/1969','12/31/2002'),format='%m/%d/%Y')

On the documentation page for DateTimeClasses, in the Examples section, there are the following two lines: format(.leap.seconds) # the leap seconds in your time zone print(.leap.seconds, tz = "PST8PDT") # and in Seattle's The second line (using print) seems to ignore the tz argument, and prints the dates in my time zone, while: format(.leap.seconds, tz =

> 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

R developers, The "tzone" attribute is stripped from a POSIXct object when the subscript command is called ("[.POISXct"). This results in dates being printed in the locale specific format after a subscript operation is applied to a POSIXct object which has cause several problems for me in the past. Here is an example of this problem under R 1.9.1: > x <-

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

Dear All- I am trying to merge two data files - they have different date formats and different times zones. I need to match up the date/time of the datasets and then invoke a conditional statement, such as: if dataC$mph is >= 12 then keep dataM$co23 for the corresponding time/date stamp. snippets of data files: *dataC.txt* LST in mph Deg DegF DegF2 % volts Deg

Inside of the anyNA() function, it will use the legacy any(is.na()) code if x is an OBJECT(). If x is a vector of POSIXct, it will be an OBJECT(), but it is also TYPEOF(x) == REALSXP. Therefore, it will skip the faster ITERATE_BY_REGION, which is typically 5x faster in my testing. Is the OBJECT() condition really necessary, or could it be moved after the switch() for the individual TYPEOF(x)

Dear R-helpers, I have a problem converting an object made with the 'chron' function to a POSIXct object: # Make date based on DOY dat <- chron(dates=232, origin.=c(month=1, day=1, year=2008)) dat #[1] 08/20/08 # Converting to POSIXct uses current timezone (Sydney): as.POSIXct(dat) #[1] "2008-08-20 10:00:00 EST" # Setting GMT timezone has no effect? as.POSIXct(dat,

Hi! I'm confused by this: > as.numeric(as.POSIXct(518400,origin="2001-01-01")) [1] 978822000 I guess the problem is that as.numeric() assumes a different origin, but cannot find any default origin. How can I get back the seconds from the POSIXct format? In other words, which the inverse function of as.POSIXct()? I've tried as.numeric and unclass() using a origin=

R 2.6.1 on a Thinkpad T60 running up-to-date Gentoo: Despite the documentation, which says: 'strftime' is an alias for 'format.POSIXlt', and 'format.POSIXct' first converts to class '"POSIXlt"' by calling 'as.POSIXlt'. Note that only that conversion depends on the time zone. strftime fails on POSIXct objects: > foo <-

I have asked this question before, and received some suggestions for work-arounds that get the job done--and they are much appreciated. But I would still like to find out if I'm missing something, and whether there is a direct way using POSIXt functions (as.POSIXct, as.POSIXlt, strptime, in particular). I have environmental data collected once per minute. Here is a subset of 3 input

In attempting to build R using rpmbuild --rebuild R-2.1.0-0.fdr.2.fc3.src.rpm on a fairly up-to-date RedHat 9 system (that is, with patches installed through May 1 2004), it failed at the make check-all step. The problem was reproducible by going into the tests directory and make test-Segfault The last lines of the saved file no-segfault.Rout.fail are > > ## c.POSIXct : > >

I have suggestions for function 'diff.default' in R. Suggestion 1: If the input is matrix, always return matrix, even if empty. What happens in R 2.15.2: > rbind(1:2) # matrix [,1] [,2] [1,] 1 2 > diff(rbind(1:2)) # not matrix integer(0) > sessionInfo() R version 2.15.2 (2012-10-26) Platform: i386-w64-mingw32/i386 (32-bit) locale: [1] LC_COLLATE=English_United

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.