Displaying 20 results from an estimated 10000 matches similar to: "Problem to convert date to number"
2012 Jun 15
2
time zones and the chron to POSIXct conversion
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
2009 Jul 20
1
Problem with as.POSIXct on dates object
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,
2004 Aug 17
3
Fwd: strptime() problem?
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
2003 Dec 15
3
Julian Dates
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"
2009 Sep 20
2
Date/Time to date & time
Hi,
Can strptime (or some other function) help me turn the following
column of a data.frame into two new columns, one as date and the other
as time, preserving the AM/PM value?
Thanks,
Mark
> B
ENTRY DATE
1 3/23/2009 6:30:00 AM
2 3/23/2009 6:30:00 AM
3 3/23/2009 6:39:00 AM
4 3/23/2009 6:39:00 AM
5 3/23/2009 6:48:00 AM
6 3/23/2009 6:48:00 AM
7 3/23/2009 7:00:00 AM
2003 Nov 12
3
Chron, as.POSIXct problem
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.
>
2003 Jul 31
4
timezones
I have some questions and comments on timezones.
Problem 1.
# get current time in current time zone
> (now <- Sys.time())
[1] "2003-07-29 18:23:58 Eastern Daylight Time"
# convert this to GMT
> (now.gmt <- as.POSIXlt(now,tz="GMT"))
[1] "2003-07-29 22:23:58 GMT"
# take difference
> now-now.gmt
Time difference of -5 hours
Note that the difference
2011 Mar 08
1
Date arithmetic coerces POSIXlt to POSIXct?
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
2003 Feb 21
1
POSIX problem in New Zealand (PR#2570)
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
2020 Oct 01
3
timezone tests and R-devel
The return value of Sys.time() today with a timezone of US/Eastern is
unchanged between 4.0.3-patched and devel, but on devel the following test
fails
all.equal(x, as.POSIXlt(x))
with
x = Sys.time()
This means that devel does not complete make tests (failure on
tests/reg-tests-2.R)
It is entirely possible that it is an error on my end, I use
export TZ="US/Eastern"
but I have been
2020 Oct 02
2
timezone tests and R-devel
Yes, the potential issue I see is that
make check
fails when I explicitly set TZ. However, I set it to be the same as what
the system reports when I login.
Details: The system (RHEL) I am working on has
$ strings /etc/localtime | tail -n 1
EST5EDT,M3.2.0,M11.1.0
$ date +%Z
EDT
$ echo $TZ
US/Eastern
On Fri, Oct 2, 2020 at 9:48 AM Sebastian Meyer <seb.meyer at fau.de> wrote:
> Thank
2014 Mar 24
1
Timezone warnings on package install in R-alpha
Dear all,
As of the current R alpha release, I'm seeing timezone-related warnings on
installing any package (including the recommended ones), which I haven't
seen before. For example,
[~/Documents/Source/R-alpha]$ bin/R CMD INSTALL ~/git/tractor/lib/reportr
* installing to library '/Users/jon/Documents/Source/R-alpha/library'
* installing *source* package 'reportr' ...
2004 Aug 18
1
Fwd: strptime() problem? - Resolved
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
2004 Apr 23
3
time zones in POSIXt
Hi,
I have two data sources. One records time in PST time zone, the other in
GMT. I want to compute the difference between the two, but don't see
how. Here is an example where I compute time difference between
identical times each (meant to be) relative to its time zone.
> as.POSIXlt("2000-05-10 10:15:00", "PST") - as.POSIXlt("2000-05-10
10:15:00",
2016 Apr 04
2
Understanding POSIXct creation on different OSes.
Hello,
Following Dirk's post here: https://github.com/Rdatatable/data.table/issues/1619
we would like to clarify if this is the right behaviour, and if so,
the rationale behind it.
Here's the summary (thanks to Dirk and Joshua):
Sys.setenv("TZ"="America/Chicago")
dates = as.Date("2016-03-02") + (0:3)*7 # four Wednesdays
# [1] "2016-03-02"
2006 Sep 01
3
Date conversion with as.POSIXct and as.POSIXlt (PR#9196)
Full_Name: Erich Neuwirth
Version: 2.3.1
OS: Windows XP, Linux
Submission from: (NULL) (131.130.135.167)
Converting Sys.Date() to a POSIX compliant time type in different ways
produces inconsistent results:
> Sys.date()
[1] "2006-09-01"
> as.POSIXct(Sys.Date())
[1] "2006-09-01 02:00:00 CEST"
> as.POSIXlt(Sys.Date())
[1] "2006-09-01"
>
2015 Dec 07
2
inconsistency in POSIXlt
The documentation for the POSIXlt class states '"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 zone and the alternate (daylight-saving) time zone. Sometimes this may
just be of length one, giving the time zone
2008 Aug 01
1
chron objects: input/output
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
2009 Nov 12
1
xts conversion problem
I have two data frames, with two columns each, the first being a Date
variable. I would like to convert them to xts objects, indexed by the
Date column. I would like to use as.Date and not as.POSIXct as the
dateformat. The puzzling fact is that it works for the first one but
not the other. Here is a screenshot of the error:
> str(DF1)
'data.frame': 367 obs. of 2 variables:
$
2019 Aug 02
4
Infrequent but steady NULL-pointer caused segfault in as.POSIXlt.POSIXct (R 3.4.4)
The R script I run daily for hours looks like this:
while (!finish) {
Sys.sleep(0.1)
time = as.integer(format(Sys.time(), "%H%M")) # always crash here
if (new.data.timestamp() <= time)
next
# ... do some jobs for about 2 minutes ...
gc()
}
Basically it waits for new data, which comes in every 10 minutes, and
do some jobs, then gc(), then loop again. It