similar to: Problems with as.POSIXct

Full_Name: Xiao Gang FAN Version: 2.4.0 OS: Windows Submission from: (NULL) (159.50.101.9) > library(chron) > as.Date(as.POSIXct(strptime("1994-01-24","%Y-%m-%d"))) [1] "1994-01-23"

Under platform i686-pc-linux-gnu arch i686 os linux-gnu system i686, linux-gnu status major 1 minor 6.1 year 2002 month 11 day 01 language R > x <- strptime(c('10/10/1969','12/31/2002'),format='%m/%d/%Y')

Hello everyone, I'm having a big trouble with which seems to be a bug in as.POSIXct() date-time conversion. I have massive GPS datasets in which each location has it's own date and time attribute. As I convert them to POSIXct format, 1300 cases (of about half a million locations) simply return NA values. I picked up a small sample of failed cases and normal cases to demonstrate the

Dear R-users, I use unlist of POSIX dates to extract the year, hour etc. With that I can search for files in my database which are in the form 'yyyymmddhh_synops.txt' However, I get stucked during midnight where unlist just gives NA's. The script is given below, the problem accurs at acc.period[16] (midnight). However when I write out the character, unlist works well. But

Date-Time-Stamp input method to correctly interpret user-specific formats:coding is 90% there - based on exmple at http://tolstoy.newcastle.edu.au/R/help/05/02/12003.html ...anyone got the last 10% please? CONTEXT: Data is received where one of the columns is a datetimestamp. At midnight, the value represented as text in this column consists of just the date part, e.g.

Dear R-Users, I have a data file with timestamps and I wanted to use POSIXct time data type to represent the respective column. I played around with the type and found a couple of issues: * there seems to be no direct way of reading datetimes into a variable. Let's say this is my file "1992-02-27 23:03:20 PST" "1992-02-27 22:29:56 PST" "1992-01-14 01:03:30 PST"

Hi all, I'm having difficulty converting a 'dates' object to a POSIXct object: testDATES<-c(35947,35971,36004,36008,36053,36066) testDATES<-chron(dates=testDATES, format = c(dates = "m/d/y"), origin=c(month = 12, day = 30, year = 1899)) >[1] 06/01/98 06/25/98 07/28/98 08/01/98 09/15/98 09/28/98 > as.POSIXct(testDATES) [1] NA NA NA NA NA NA

There is something wrong, I think, with the date-time conversion from a numeric value if you use Central European Time (CET) as timezone. Examples from R: If I use the GMT time zone it is OK, I get the same time back from as.POSIXct as I entered > as.POSIXct(as.numeric(strptime("30/01/2012 13:00:00", format="%d/%m/%Y >

Full_Name: Allen McIntosh Version: 2.0.0 OS: RedHat 9.0 Submission from: (NULL) (67.80.175.118) The POSIX time printing routine gives strange results when asked to print a time that is exactly midnight: TZ=CST6CDT R -q --no-save > strptime("10/5/2004 00:00:01 CDT", "%m/%d/%Y %H:%M:%S %Z") [1] "2004-10-05 00:00:01" > strptime("10/5/2004 00:00:00

If I take the following simple data: YEAR MONTH DAY WEIGHT.KG 2003 10 6 1.2 2003 10 12 1.2 2003 10 16 1.3 and format the date data and plot it: dates <- strptime(paste(DAY,MONTH,YEAR),"%d%m%Y") plot(c(min(dates),max(dates)),c(0,max(WEIGHT.KG)), xlab="Date",ylab="Weight (kg)",type="n") lines(dates,WEIGHT.KG) points(dates,WEIGHT.KG) I find that the

Dear list-members, I would like to calculate the difference between two points in time. To convert a 'time (GMT)'-character with the format "1/1/1999 01:01:01" into an object of class "POSIXct"', I first use the strptime() as suggested in the details help(as.POSIXct). e.g. starttime<-strptime("1/1/1999 01:01:01",format="%d/%m/%Y %H:%M:%S")

For the r script below >datestr <- "01/01/2004" >as.POSIXct(as.Date(datestr, "%d/%m/%Y")) I get the following output "2003-12-31 18:00:00 Central Standard Time" Why is the date a day before. I guess its something to do with the time, but is there a way to get it to return 2004-01-01 instead? Thanks in advance... -Sandeep [[alternative HTML version

Hi, I have some dates that are giving me a problem, in general the dates look like this: free.dates[60:61] [1] "2009-05-21 23:45:00 GMT" "2009-05-22 00:00:00 GMT" but for some reason, when taken "alone", they look like this: free.dates[60] [1] "2009-05-21 23:45:00 GMT" free.dates[61] [1] "2009-05-22 GMT" # the time component is gone, and

Hi everybody When I try example of strptime x <- c("1jan1960", "2jan1960", "31mar1960", "30jul1960") z <- strptime(x, "%d%b%Y") The result is; > z [1] NA NA NA NA I have got the same result with complete form of month but not with numeric form. Any idea? [[alternative HTML version deleted]]

I thought this is a common question but rseek/google searches don't yield any relevant hit. I have a matrix of character strings, which are time stamps, > time.m[1:5,1:5] [,1] [,2] [,3] [,4] [,5] [1,] "08:00:20.799" "08:00:20.799" "08:00:20.799" "08:00:20.799" "08:00:20.799" [2,]

Dear Jim and dear Enrico, thank you for your replies. Unfortunately your hints didn't solve my problem, and I am getting mad. Can I show you my whole process? I will be as quick as possible. I start from a data frame called Snow of the form year month day hh mm hs 2007 11 19 0 0 0.00 2007 11 19 0 30 0.00 2007 11 19 1 0 0.00 2007 11 19 1 30 0.00 2007 11 19 2 0 0.00 2007 11 19 2 30 0.00 2007 11

I've run into a problem with the datetime axis generated by axis.POSIXct. It appears a similar issue was discussed in October 2003 under the subject line "datetime data and plotting" (see https://stat.ethz.ch/pipermail/r-help/2003-October/039071.html), but I wasn't able to determine whether there is a straightforward solution. The code below produces a graph with apparently

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"

Hi, I think that there is something that I am misunderstanding in creating tables using dates that are of class POSIXct. Consider: > x <- data.frame(date = as.POSIXct(strptime(c(rep("2002-10-17", 4), rep("1999-12-08", 2)), format = "%Y-%m-%d"))) > x date 1 2002-10-17 2 2002-10-17 3 2002-10-17 4 2002-10-17 5 1999-12-08 6 1999-12-08 > table(x$date)