similar to: Extracting day of month from Date objects

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,

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

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, 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 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

Full_Name: Alec Stephenson Version: 1.6.0 OS: linux Submission from: (NULL) (148.88.138.5) Appears to be a sign error in as.POSIX(lt/ct) > library("chron") The following is fine, with default origin. > tmp <- chron(1:2, origin = c(1,1,1970)) > as.POSIXlt(tmp) [1] "1970-01-02 01:00:00 GMT" "1970-01-03 01:00:00 GMT" These are not. > tmp <-

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 >

Hi, I have a column in a dataframe in the form of: > as.vector(SLDATX[1:20]) [1] "1/6/1986" "1/17/1986" "2/2/1986" "2/4/1986" "2/4/1986" [6] "2/21/1986" "3/6/1986" "3/25/1986" "4/6/1986" "4/10/1986" [11] "4/23/1986" "4/30/1986" "5/8/1986"

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

Hey all, Virgin post to this list - hope I've got it right ;o) I've been learning R intensively the last two weeks and gone from newbie status to *reasonably* comfortable with it. Here's an issue I just cannot solve however as it appears to be some kind of bug in R itself. But I won't claim that for sure. I have a function as follows: FindHighRow <- function(searchVector,

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 , I am trying to convert the date as factor to date using "as.date" function in R. I have the date in the following format 2008-01-01 02:30 I tried to use the following command : as.Date(mydata$Date, format="%y-%m-%d ") Can somebody help me with this ? I was able to convert the format with no hour but getting difficulty with hour included. Thank you.

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

Hi list, Could someone explain to me why the following result is not a integer? > difftime(strptime("24NOV2004", format="%d%b%Y"), strptime("13MAY2004", >format="%d%b%Y"), units="days") Time difference of 195.0417 days I'm using R2.12.0 on WinXP. Thanks! ...Tao

Hola a todos: Debe de ser una tontería, pero no consigo saber porque la siguiente linea no devuelve la fecha actual: as.Date(as.numeric(Sys.time())) He hecho esa prueba porque no consigo pasar un numero convertido a partir de una fecha y modificado a fecha de nuevo. Gracias por adelantado. Un saludo, Alberto. [[alternative HTML version deleted]]

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. >

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

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

The US water year extends from 01 October yyyy-1 through 30 September yyyy and is referenced by the year starting on the included 01 January yyyy. I'd like to be able to find the annual means for the water year. To do so I've taken the input date-time, which is in the usual format "1991-10-07 10:35:00" changed it by: w$d<-as.POSIXct(w$date.time) Now I can add an

Dear useRs, I'm struggling again with date-related stuff: I am using R to draw water levels at certain measuring stations. My data comes as a tab-delimited text file and looks like this: DATUM P1 P2 ... 2006-11-16 425.21 423.99 2006-12-15 425.12 423.97 2007-01-16 425.16 424.06 ... (measurements started in July 2004 and still continue on a monthly or bi-weekly basis) This