similar to: years from as.POSIXlt

How can I extract only the time component from an POSIXlt object? For example if I try the following it still returns both the date and time... >as.POSIXlt(tr.date[1]) [1] "2010-10-18 21:46:53" >as.POSIXlt(tr.date[1],"%H:%M:%S") [1] "2010-10-18 21:46:53" round and trunc don't help... is there an "as.Time" equivalent to as.Date ? Thanks,

hello, I have a vector of factors > str(rcptdt) Factor w/ 51 levels "1/10/03","1/13/03",..: > length(rcptdt) [1] 87 which i want to convert to class POSIXlt to extract the day, so: a1<-format(rcptdt,"%m/%d/%y") > length(a1) [1] 87 and: a2<-strptime(a1, "%m/%d/%y") str(a2) `POSIXlt', format: chr [1:87] "2002-04-18"

Dear all, I import my data from a csv-file containing one row with date-entries. How can I tell R to treat this data as dates? I've tried to bring it in character-format (as.charachter()) followed by as.POSIXlt() but I get an error message, that the character string is not in a standard unambiguous format, although the date is of format yyyy-mm-dd (what is standard format according to R

The interface for dates in R is a little confusing to me. I want to create a vector of Date objects from vectors of years, months, and days. One solution I found is: years <- c(1991, 1992) months <- c(1, 10) days <- c(1, 2) dates <- as.Date(ISOdate(years, months, days)) But, in this solution the ISOdate function converts the vectors into characters, which can cause serious

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

My environment.rb contains config.time_zone = ''UTC'' If my understanding is correct, rails should assume time values coming from the database are UTC, and since config.time_zone is set to ''UTC'', it should not try to convert the times. Instead, rails is assuming that the db values are Eastern (my local zone) and is incorrectly adding four hours to convert to

Hello, I have some data that has dates in the form 27.02.37. I convert them to a date object as follows: as.Date(data$date,format="%d.%m.%y") But this gives me years such as 2037 when I would like them to be 1937. I thought of trying to take off some time i.e. as.Date(camCD$DoB,format="%d.%m.%y") - 100*365 But that doesn't seem to work out correctly. Any ideas how to

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

Hello, I was hoping for advice regarding resolving the above error. I have a csv file that contains the following variable: $ Order.Made.Date : Factor w/ 299 levels "1-Apr-08","1-Aug-05",..: 278 285 91 286 159 132 108 261 282 147 ... I want to calculate a variable named F.length, which is today's date minus the values contained in the variable:

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 >

Hello r-help, I'm trying to split a character vector of dates of the form "dd-mmm-yy" into component days, months and years. But > library(chron) > testdate<-as.POSIXlt(strptime("17-Sep-98","%d-%b-%y")) > testdate [1] "1998-09-17" > months(testdate) [1] "September" # which is fine, but for days and years I get >

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 : > >

Hello, everyone I wonder if R has something similar to Excel function EDATE(start_date; months) which returns a serial number of the date that is the indicated number of months before of after the start date. Example (the second column EDATE(first_column; -6)): 01.01.1999 01.07.1998 02.02.1999 02.08.1998 06.03.1999 06.09.1998 I am working with a zoo object where the row names are dates and for

Hi, I would like to check which rows of 'types.prev' matrix pop up in 'types', following R in-built procedure. I tried 'match' function but it works in case of the one dimensional vectors. Will appreciate any suggestions. best, robert > types edate K [1,] 20060819 12.5 [2,] 20060819 17.5 [3,] 20060819 22.5 [4,] 20070217 12.5 [5,] 20060617 10.0

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

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. >

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

Hi list, I'm trying to turn a date into something productive. (Not what you may be thinking....) I want three functions so I could take a "date" object and get the day of week, month, and year from it. xx <- as.Date("2006-01-05") month(xx) equal 1 day(xx) equal 5 year(xx) equal 2006 I'm aware of the weekdays() and months() functions in the base package. But

Hi, I'm a bit confused how julian() works. If I understand right, it returns the number of days since the origin. I have a vector: > SLDATX[1:10] [1] "1986-01-06" "1986-01-17" "1986-02-02" "1986-02-04" [5] "1986-02-04" "1986-02-21" "1986-03-06" "1986-03-25" [9] "1986-04-06"

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