Displaying 20 results from an estimated 4000 matches similar to: "Some help with dates."
2005 Oct 06
2
isdst
Can someone, please, explain the difference is results below (notice
the isdst value)
> unlist(as.POSIXlt('2005-7-1'))
sec min hour mday mon year wday yday isdst
0 0 0 1 6 105 5 181 1
> unlist(as.POSIXlt(as.Date('2005-7-1')))
sec min hour mday mon year wday yday isdst
0 0 0 1 6 105 5 181 0
2020 Oct 23
2
The presence/absence of `zone` in POSIXlt depending on time zone as a cause of possible inconsistences?
Dear all,
I have just detected what seems a minor inconsistence with data types. If one unlists a POSIXlt time with GMT zone gets a numeric vector, since the POSIXlt list has no `zone` element, while if one unlists a POSIXlt time with a non GMT zone (also non specifying tz if the Sys.timezone is not GMT) gets a character vector due to including the `zone` element.
> x <-
2007 Dec 11
3
Wrong length of POSIXt vectors (PR#10507)
Full_Name: Petr Simecek
Version: 2.5.1, 2.6.1
OS: Windows XP
Submission from: (NULL) (195.113.231.2)
Several times I have experienced that a length of a POSIXt vector has not been
computed right.
Example:
tv<-structure(list(sec = c(50, 0, 55, 12, 2, 0, 37, NA, 17, 3, 31
), min = c(1L, 10L, 11L, 15L, 16L, 18L, 18L, NA, 20L, 22L, 22L
), hour = c(12L, 12L, 12L, 12L, 12L, 12L, 12L, NA, 12L,
2003 Aug 13
1
Problems with addition in big POSIX dates
Have you noticed any problems with big dates (>=1/1/2040) in R?
Here is the bit of code that I'm having trouble with:
> test.date <- strptime("1/1/2040",format="%m/%d/%Y")
>
> unlist(test.date)
sec min hour mday mon year wday yday isdst
0 0 0 1 0 140 0 0 0
>
> date.plus.one <- as.POSIXct(test.date) +
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
2010 Oct 01
3
Converting a dataframe column from string to datetime
Hi,
I have a dataframe column of the form
v<-c("Fri Feb 05 20:00:01.43000 2010","Fri Feb 05 20:00:02.274000 2010","Fri Feb 05 20:00:02.274000 2010","Fri Feb 05 20:00:06.34000 2010")
I need to convert this to datetime form. I did the following..
lapply(v,function(x){strptime(x, "%a %b %d %H:%M:%OS %Y")})
This gives me a list that looks like
2017 May 17
2
R-3.4.0 fails test
After installing R-3.4.0 I ran 'make check' which halted here:
$ > tail reg-tests-1d.Rout.fail -n 16
> ## format()ing invalid hand-constructed POSIXlt objects
> d <- as.POSIXlt("2016-12-06"); d$zone <- 1
> tools::assertError(format(d))
> d$zone <- NULL
> stopifnot(identical(format(d),"2016-12-06"))
> d$zone <- "CET" # =
2017 May 17
2
R-3.4.0 fails test
After installing R-3.4.0 I ran 'make check' which halted here:
$ > tail reg-tests-1d.Rout.fail -n 16
> ## format()ing invalid hand-constructed POSIXlt objects
> d <- as.POSIXlt("2016-12-06"); d$zone <- 1
> tools::assertError(format(d))
> d$zone <- NULL
> stopifnot(identical(format(d),"2016-12-06"))
> d$zone <- "CET" # =
2010 Dec 27
1
Can't merge on datetime?
x = structure(list(date = structure(list(sec = c(0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0), min = c(0L, 0L,
0L, 0L, 0L, 0L, 0L, 0L, 0L, 0L, 0L, 0L, 0L, 0L, 0L, 0L, 0L, 0L,
0L, 0L, 0L), hour = c(0L, 0L, 0L, 0L, 0L, 0L, 0L, 0L, 0L, 0L,
0L, 0L, 0L, 0L, 0L, 0L, 0L, 0L, 0L, 0L, 0L), mday = c(1L, 2L,
3L, 4L, 5L, 8L, 9L, 10L, 11L, 12L, 15L, 16L, 17L, 18L, 19L, 22L,
23L, 24L,
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
2002 May 21
1
I() fails on objects of class POSIXct (PR#1587)
Although the documentation is somewhat sketchy, I() can be used to create
objects of class AsIs:
> I("a")
[1] "a"
attr(,"class")
[1] "AsIs" "character"
> I(4)
[1] 4
attr(,"class")
[1] "AsIs" "numeric"
> I(4 + 0i)
[1] 4+0i
attr(,"class")
[1] "AsIs" "complex"
>
This
2005 Dec 19
3
given a mid-month date, get the month-end date
I have a vector of dates.
I wish to find the month end date for each.
Any suggestions?
e.g.
For 12/15/05, I want 12/31/05,
For 10/15/1995, I want 10/31/1995, etc
__________________________________________________
[[alternative HTML version deleted]]
2013 Feb 08
2
Can not melt data.frame
I realize it's -12C and we're having the next best thing to a blizzard but why can I not melt this data frame.
I am missing something terribly obvious but I just don't understand what the error message is saying.
John Kane
Kingston ON Canada
Code and aata below
#================================================#
library(reshape2)
melt(mydata, id.vars = c("date"))
2011 Jun 22
2
strange date problem - May 3, 1992 is NA
> is.na(strptime("5/2/1992", format="%m/%d/%Y"))
[1] FALSE
> is.na(strptime("5/3/1992", format="%m/%d/%Y"))
[1] TRUE
Any idea what's going on with this? Running strptime against all dates
from around 1946, only 5/3/1992 was converted as "NA". Even stranger,
it still seems to have a value associated with it (even though is.na
thinks
2010 Sep 03
1
Incorrect formatted output after subtracting non-integer seconds from POSIXt origin
> x<-as.POSIXct("1970-1-1", tz="UTC")-.5
> y<-as.POSIXct("1970-1-1", tz="UTC")+.5
> x==y
[1] FALSE # of course
but x and y "appear" to be the same when formatted, even with extra
precision:
> format(x, format="%Y-%m-%d %H:%M:%OS2")
[1] "1970-01-01 00:00:00.50"
> format(y, format="%Y-%m-%d
2011 Feb 19
1
problem in plotting numeric x by POSIXt class with lattice
# hi all,
# I'm trying to plot temperatures by date in a trellis plot by their
stations
# I'm plotting the following data.frame
library(lattice)
h <- structure(list(station_name = structure(c(3L, 4L, 2L, 10L, 11L,
12L, 6L, 7L, 5L, 8L, 9L, 3L, 4L, 2L, 10L, 11L, 12L, 6L, 7L, 5L,
8L, 9L, 3L, 4L, 2L, 10L, 11L, 12L, 6L, 7L), .Label = c("Ashqelon",
"Beer Sheva",
2009 Nov 01
4
convert list to Dataframe
Hi. I have a huge list called twitter:
> dim(twitter)
NULL
> str(twitter)
List of 1
$ :Classes 'PlainTextDocument', 'TextDocument', 'character' atomic
[1:35575] 11999;10:47:14;20;10;2009;ObamaLouverture;Trails Mixed Lessons For
Governance From Campaigner-in-chief: President obama jumps campaign 09
tuesday..
2011 Mar 10
1
Timezone issue with strftime/strptime and %z and %Z
Hello!
I've been trying to get this right for quite a while now and fear
there is an easy solution I just don't see. I did not have this
problem in Linux, and I searched r-help and Google but did not find a
solution, but of course I am grateful for and resources I might not
have found our not understood yet.
I try to parse a time stamp with time zone. I essentially just want to
parse the
2008 Feb 17
1
How to make a vector/list/array of POSIXlt object?
Hi Guys,
I'm cooking up my time series code. I want a data frame with first column as timestamp in POSIXlt format.
I hit on this the problem of how to create an array/list/vector of POSIXlt objects. Code is as follows
> dtt=array(dim = 2)
> t=as.POSIXlt( strptime("07/12/07 13:20:01", "%m/%d/%Y %H:%M:%S",tz="GMT"))
> dtt
[1] NA NA
> t
[1]
2007 Jan 17
2
problem with unlist POSIX date at midnight
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