similar to: Floating point precision causing undesireable behaviour when printing as.POSIXlt times with microseconds?

Dear list, I'm a bit puzzled by an ambiguity with respect to the representation of micro-/milliseconds when using 'POSIXlt' objects. It seems that the last digit of the 'sec' attribute sometimes seems to differ from the digits shown when printing the 'POSIXlt' object. You'll find a little SO post with some example code here:

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 I have a string which contains microseconds, can anyone help on constructing this in to a time object, with the microseconds, that I can take to a ZOO file? Thanks Sean > UK[1,3] [1] "17:09:53.824" > UK[1,1] [1] "2007-12-11 00:00:00" > mydates <- paste( substr(UK[,1], 1, 10), UK[,3]) > mydates[1] [1] "2007-12-11 17:09:53.824" >

In?function?'Summary.Date'?in?dates.R?, ..1 could?be?used?instead?of ...elt(1L) In?function?'format.POSIXlt'?in?datetime.R?, unlist(unclass(x)[1L:3L],?use.names=FALSE) could?be?used?instead?of unlist(`names<-`(unclass(x)[1L:3L],?NULL)) Also, the fragment secs <- x$sec[f0]; secs <- secs[is.finite(secs)] could be put inside if(np?>=?1L)

Dear useRs, I am sure this is a fairly simple problem, but I just cannot get my head around it. I have a dataframe which contains several factor variables. I can use table() to tell me how many different combinations there are of these variables. What I should like to do is to add a column to my original dataframe which labels each row according to the unique combination of factors. E.g. in

I've been searching for patterns in why some POSIXlt objects have the zone and gmtoff components and some don't and why gmtoff is sometimes NA when the zone is known. Is there a pattern or is it just that the additional fields and workarounds were added in an ad hoc way? E.g., as.POSIXlt adds the zone and gmtoff components for all strings and logical NA inputs if the time zone is not

Dear R core team Please apologize for posting the same question twice on R-help and R-devel. Since I was not sure which list is appropriate I tried R-help (Tue Mar 22), but got no answer. Now I do not know if the formulation of my question was unclear or the question is not so easy to answer or to easy (what I do not hope). My problem: I create a new S4 class, containing one slot, data (of

On Tue, Dec 6, 2016 at 6:37 AM, <frederik at ofb.net> wrote: > Hi all, > > I ran into a segfault while playing with dates. > > $ R --no-init-file > ... > > library(lubridate); d=as.POSIXlt(floor_date(Sys.time(),"year")); d$zone=NULL; d$zone=""; d > If you're asking about a bug in R, you should provide a *minimal* reproducible

?Hi again, I take advantage of my previous mail to ask you a question for which I was looking for an answer when detected the behaviour I previously told. In the help of DataTimeClasses one can read: "POSIXlt" objects will often have an attribute "tzone", a character vector of length 3 giving the time zone name from the TZ environment variable and the names of the base time

In the base package, as.POSIXct() is an S3 generic function, but as.POSIXlt() is not. As shown below, the current implementation is already crying out to be refactored into a generic function with methods for various classes. It calls "inherits" five times. Not only is this bad style, it also disallows me or anyone else from making as.POSIXlt() work with other kinds of time-ish

Dear R gurus I've a question concerning the transformation of a new S4 class (that I defined) and the existing class "POSIXlt". I did the following: ## Definition of the new class: setClass("dtime", representation(data = "POSIXlt"), prototype(data = as.POSIXlt("2004/06/01"))) ## Transformation between the new class "dtime"

>>>>> Joshua Ulrich <josh.m.ulrich at gmail.com> >>>>> on Tue, 6 Dec 2016 09:51:16 -0600 writes: > On Tue, Dec 6, 2016 at 6:37 AM, <frederik at ofb.net> wrote: >> Hi all, >> >> I ran into a segfault while playing with dates. >> >> $ R --no-init-file >> ... >> >

Hi Joshua, Thank you for minimizing my test case. > > Hope I'm not doing something illegal... > > > You are. You're changing the internal structure of a POSIXlt object > by re-ordering the list elements. You should not expect a malformed > POSIXlt object to behave as if it's correctly formed. You can see > it's malformed by comparing it's

Hi, I am encountering a strange error in POSIXlt... anyone got a clue? > as.POSIXlt("1982-01-01") Error in as.POSIXlt.character("1982-01-01") : character string is not in a standard unambiguous format > as.POSIXlt("1992-01-01") [1] "1992-01-01" > as.POSIXlt("1972-01-01") [1] "1972-01-01" > as.POSIXlt("1962-01-01")

Hi, I'm encountering a strange error in POSIXlt... anyone got a clue on this? > as.POSIXlt("1982-01-01") Error in as.POSIXlt.character("1982-01-01") : character string is not in a standard unambiguous format > as.POSIXlt("1992-01-01") [1] "1992-01-01" > as.POSIXlt("1972-01-01") [1] "1972-01-01" >

Tracking down this bug was joint work with Jermoe Asselin (jerome at hivnet.ubc.ca) and Patrick Connolly (p.connolly at hortresearch.co.nz). We collectively were able to determine that this is a problem in both Windows 2000 and in Linux and by testing it in our three time zones that it seems to be daylight savings time related. Conversion of POSIXlt datetimes to POSIXct appears to have problems.

Hi Guys, I'm cooking up my time series code. I want a data frame with first column as timestamp in POSIXlt format. I hit on this the problem of how to create an array/list/vector of POSIXlt objects. Code is as follows > dtt=array(dim = 2) > t=as.POSIXlt( strptime("07/12/07 13:20:01", "%m/%d/%Y %H:%M:%S",tz="GMT")) > dtt [1] NA NA > t [1]

Hi all, following sample code illustrates the problem : Date1 <- Date2 <- as.POSIXlt(seq.Date(as.Date("2010-04-01"),as.Date("2011-04-01"),by='day')) identical(Date1,Date2) all.equal(Date1,Date2) identical() gives the correct answer. As there is no all.equal method for POSIXlt objects, all.equal.list is used instead. Subsetting using [[]] doesn't work

I have a data frame that contains dates, but when I use as.POSIXlt() I lose the hours on all records. I traced this down to a particuar hour which causes the issue... > as.POSIXlt('2004-10-31 02:00:00') [1] "2004-10-31" > as.POSIXlt('2004-10-31 03:00:00') [1] "2004-10-31 03:00:00" How do I tell as.POSIXlt() to ignore daylight savings and just convert to

This may not actually be an R/Splus problem, but it started off that way ..... ===+===+===+===+===+===+===+===+===+===+===+===+===+===+===+===+===+===+=== Executive summary: ================== Simulations involving extreme value distributions seem to ``work'' when the underlying distribution is exponential(1) or exponential(2) == chi-squared_2, but NOT when the underlying distribution is