similar to: POSIXlt vs POSIXct

In trying to use as.Date(), I've come across the conversion of POSIXlt to POSIXct when a POSIXlt variable is included in a data frame: my_POSIX <- strptime(c("11-09-2006", "11-10-2006", "11-11-2006", "11-12-2006", "11-13-2006"), "%m-%d-%Y") str(my_POSIX) my_Date <- as.Date(my_POSIX) str(my_Date) data <- format(my_Date)

Full_Name: Erich Neuwirth Version: 2.3.1 OS: Windows XP, Linux Submission from: (NULL) (131.130.135.167) Converting Sys.Date() to a POSIX compliant time type in different ways produces inconsistent results: > Sys.date() [1] "2006-09-01" > as.POSIXct(Sys.Date()) [1] "2006-09-01 02:00:00 CEST" > as.POSIXlt(Sys.Date()) [1] "2006-09-01" >

Hi. This feels like a bug to me, or at least an undocumented feature, but I thought I'd see what people here thought of it. Consider a POSIXlt object like this one: > a <- as.POSIXlt ("2011-01-23 12:45:45") > class (a) [1] "POSIXlt" "POSIXt" Fine. Now, if I do some arithmetic on that object, the result is converted to POSIXct. > class (a

Dear R users, Given this data: x <- seq(1,100,1) dx <- as.POSIXct(x*900, origin="2007-06-01 00:00:00") dfx <- data.frame(dx) Now to play around for example: subset(dfx, dx > as.POSIXct("2007-06-01 16:00:00")) Ok. Now for some reason I want to extract the datapoints between hours 10:00:00 and 14:00:00, so I thought well: subset(dfx, dx >

Running under Windows XP 64 bit, as.POSIXlt()/as.POSIXct() seem to think that US time zones (EST5EDT, MST7MDT) switched from daylight savings back to standard time on Oct 28, 2007, whereas the switch is actually on Sun Nov 04, 2007. Examples: > Sys.timezone() [1] "Mountain Daylight Time" > as.POSIXct("2007-10-30 12:38:47") [1] "2007-10-30 12:38:47 Mountain

Hello, I found rather surprising the behaviour of POSIXct and POSIXlt classes when combined with min and tapply. The details can be deduced from the script below: ############# Start of the script #################### before <- Sys.time() Sys.sleep( 1 ) now1 <- now2 <- Sys.time() my.times <- c( before, now1, now2 ) class( my.times ) ## [1] "POSIXct"

Dear Listers, I have encountered a strange problem using diff() and POSIXt: dts<-c("15/4/2003","15/7/2003","15/10/2003","15/04/2004","15/07/2004","15/10/2004","15/4/2005","15/07/2005","15/10/2005","15/4/2006") dts <- strptime(dts, "%d/%m/%Y") class(dts) [1] "POSIXt"

Dear Listers, I have encountered a strange problem using diff() and POSIXt: dts<-c("15/4/2003","15/7/2003","15/10/2003","15/04/2004","15/07/2004","15/10/2004","15/4/2005","15/07/2005","15/10/2005","15/4/2006") dts <- strptime(dts, "%d/%m/%Y") class(dts) [1] "POSIXt"

A reply from stackoverflow suggests I might have hit this bug: https://sourceware.org/bugzilla/show_bug.cgi?id=14023 I can confirm that this glibc bug affects my system (latest CentOS 7). However, as far as I know, R is not multithreaded in its core. Is it possible that some library triggered this? Regards, Steve Tomas Kalibera <tomas.kalibera at gmail.com> ?2019?8?2??? ??4:59??? >

The R script I run daily for hours looks like this: while (!finish) { Sys.sleep(0.1) time = as.integer(format(Sys.time(), "%H%M")) # always crash here if (new.data.timestamp() <= time) next # ... do some jobs for about 2 minutes ... gc() } Basically it waits for new data, which comes in every 10 minutes, and do some jobs, then gc(), then loop again. It

Hello, I searched the archives but could not come to a solution. I have to two columns of information t_start_cdt looks like: > t_start_cdt[1:4] [1] "2003-07-09 11:02:25" "2003-07-09 11:10:25" "2003-07-09 11:30:25" [4] "2003-07-09 12:00:25" > class(t_start_cdt) [1] "POSIXt" "POSIXlt" t_end_cdt looks like: > t_end_cdt[1:4]

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 : > >

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 <-

Hello folks, I found a strangeness while experimenting with POSIXct vectors and lists. It seems that coerced NA's aren't "real" NAs, at least as considered by is.na()? > date_vec = c(as.POSIXct(now()), as.POSIXct(now()+1),NA,"b") > date_vec [1] "2012-08-22 15:00:46 COT" "2012-08-22 15:00:47 COT" NA [4] NA Warning message: In

When I try to do linear interpolation between financial contracts with maturities on different dates in different months I have come across some behavior I haven't seen before. I have a data frame in R which is loaded from an access database so I can't provide a working example. It was loaded using this code: > dbPath <- "H:/pathToDB/DB.mdb" > channel <-

Hey R folks, i found some strange (to me) behaviour with chron to POSIXct conversion. The two lines of code result in two different results, on ewith the correct time zone, one without: library(chron) as.POSIXct(chron('12/12/2000'), tz = 'UTC') as.POSIXlt(chron('12/12/2000'), tz = 'UTC') Only the code below would give me a POSIXct object with the correct time

POSIXct/lt supports fractional seconds (see Sub-second Accuracy section of man page), but there seem to be some inconsistencies in their handling. Converting to POSIXlt and back does not give back the same time for times before the origin: > t0 <- as.POSIXct('1934-01-05 23:59:59.00001') > t0 [1] "1934-01-06 00:00:00 EST" # rounding issue, see below >

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

1) Why did you submit this *twice*, as PR#7826 and PR#7827? Please don't be so careless of the volunteers' time. 2) > print.POSIXct function (x, ...) { print(format(x, usetz = TRUE, ...), ...) invisible(x) } is definitely *not* implicated. (Use of ... in two places is correct.) 3) On FC3: > unusual_and_faults Error: protect(): protection stack overflow >

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,