similar to: as.POSIX (PR#2222)

Full_Name: alec stephenson Version: 1.6.0 OS: linux Submission from: (NULL) (148.88.138.5) The documentation for the function require is incorrect. The file library.Rd has in its arguments section \item{quietly}{a logical. If \code{TRUE}, a warning will not be printed if the package cannot be found.} which is incorrect, as a warning message is always given if the package is not

Hi, One of the big decisions when writing code is how to handle dates and times. Gabor Grothendieck provided an excellent overview of the issue in his R News 4/1 (2004) article, and many users and developers are probably using it as a guide. The proposed guideline is to use the simplest class required; as Gabor put it "use Date if possible, otherwise use chron, and otherwise use

Full_Name: Arni Magnusson Version: 1.6.2 OS: Windows XP Submission from: (NULL) (210.48.49.68) Hi there. I'm experiencing unexpected behaviour from as.POSIXct: > as.POSIXct("1969-12-24") [1] "1969-12-23 23:00:00 New Zealand Standard Time" > as.POSIXlt("1969-12-24") [1] "1969-12-24" > as.POSIXlt("1969-12-24")+1 [1] "1969-12-23

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

The problem with POSIXt is that you must consider timezones and daylight vs. standard time issues even if you don't want to. This violates modularity (viz. your routines becomes coupled to unrelated information) and leads to subtle errors where different routines are assuming different time zones. The problem is that the time, date, day of the week, month, etc. of a date depend on its

Hi list, I have some questions regarding 1) conversion of date + time characters to chron 2) formatting chron object printing Regarding (1), Gabor's Rnews 2004 4/1 article has been indispensible, but I often work with files where dates and times are contained in a single field. In this case, I would like to control input/output of chron objects when each observation of date and time is

I tried the code that Richard O'Keefe posted last week, to wit: library(chron) ymd.to.POSIXlt <- function (y, m, d) as.POSIXlt(chron(julian(y=y, x=m, d=d))) n <- 100000 y <- sample(1970:2004, n, replace=TRUE) m <- sample(1:12, n, replace=TRUE) d <- sample(1:28, n, replace=TRUE) system.time(ymd.to.POSIXlt(y, m, d)) [1] 8.78 0.10

Hi. I frequently convert date and time data to and from character representations. I'm frustrated with chron, because 'seconds' are required to create a time object (my input data never has seconds). More importantly, I cannot make chron print the format 12/30/2006 (which my output data requires). I really like the format flexibility of strftime() and strptime(), but of course

I know that this is correct: library(chron) x = dates("01-03-04", format="d-m-y", out.format="day mon year") print(x) It gives me the string "01 Mar 2004" which is correct. I also know that I can say: print(day.of.week(3,1,2004)) in which case he says 1, for today is monday. My question is: How do I combine these two!? :-) I have a

Hi Gabor and everybody; Thanks Gabor, with the alternative step you've told me the problem is resolved. Comparing the two procedures: Extract from the source 'character' data: > rain$ts[2039:2046] [1] "25/03/2000 22:00:00 UTC" "25/03/2000 23:00:00 UTC" [3] "26/03/2000 00:00:00 UTC" "26/03/2000 01:00:00 UTC" [5] "26/03/2000 02:00:00

I've always found the chron library to be useful for tasks like this: > x <- round(runif(10)*100000, digits=0) > y <- as.Date(x, origin="1970-01-01") > library(chron) > days(y) [1] 7 25 26 25 10 24 1 31 12 8 31 Levels: 1 < 2 < 3 < 4 < 5 < 6 < 7 < 8 < 9 < 10 < 11 < 12 < 13 < ... < 31 Notice that it returns the days as

Dear R-help, Please can someone explain how to put a column name on an output data.frame. ##Starting with a data.frame with 3 columns (d$Year, d$NoIndiv, d$wtd_tl) yr_ind <- split (d$NoIndiv, d$Year) yr_tl <- split (d$wtd_tl, d$Year) ann_ind <- sapply (yr_ind, sum) ann_tl <- sapply (yr_tl, sum) av_tl <- ann_tl/ann_ind d2<- data.frame (av_tl) ##This gives me a data.frame

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. >

Thanks to Joshua Wiley for turning me on to ggplot2. I am making a plot using this: p <- ggplot(dallas, aes(x = offense_hour)) + geom_bar() + coord_polar() Dallas is a data frame, and offense_hour is a column with chron objects from the chron library. In this case, the chron object was created with the times function. It is only a time (H:M:S) with no date attached. The plot shows up fine,

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,

the date were created with chron with this argument format=c(dates="Y/m/d", times="H:M:S")) so I have the dates being displayed as (10/06/22 12:00:00) I would like to have them displayed as "2010-06-22 12:00:00" or "%Y-%m-%d %H:%M:%S" and then I can convert these for mergeing with another data frame x <- (structure(c(14464, 14464.0104166667,

Hello, all; I get an unexpected result when trying to plot a probability histogram with R1.9.1 on windows xp: #with the following code: > x <- runif(100,0,1) > hist(x) > hist(x, freq=F) > h <- hist(x, freq=F) > summary(h) # Length Class Mode #breaks 11 -none- numeric #counts 10 -none- numeric #intensities 10 -none- numeric #density 10

Hi R users, I have a maybe small problem which I cannot solve by myself. I want to convert "chron" "dates" "times" (04/30/06 11:35:00) to a number with as.POSIXct. The Problem is that I can't choose different timezones. I always get "CEST" and not "UTC" what I need. date = as.POSIXct(y,tz="UTC") "2006-04-30 11:35:00

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 =

To the R development team; I found an unusual behavior in zoo when I upgraded to R 2.11.0 - it abruptly terminated when I performed certain operations on large zoo objects. I sent an e-mail to Achim Zeileis and he said this was a potential bug that I should report to the R development team. The details are given below in the thread below. Basically, I can crash R with this code: library(zoo)