similar to: write.table read.table with Dates

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",

Conversion of a data frame to a matrix using as.matrix() when a column of the data frame is POSIXt and all other columns are numeric has changed in R 1.9.0 from R 1.8.1. The new behavior issues a warning message and converts to a character matrix. In R 1.8.1, such an object was converted to a numeric matrix. Here is an example. #### R 1.9.0 #### > foo <- data.frame(

I’m trying to export a file from R to excel using the xlsReadWritePro function and I keep getting the error below. I get the same error when I use the oledatetime function. My current date format is mm/dd/yyyy, which is how I want it in excel. Also is there anyway to export different datasets to multiple sheets similar to the ods function in SAS? <?xml:namespace prefix = o ns =

Dear list: working with date/times I have come across a problem that ISOdate and ISOdatetime are too slow on large vectors of data. I was surprised just until I looked at the implementation and the man page: "ISOdatetime and ISOdate are convenience wrappers for strptime". In other terms, they convert data to character representation first in order to create a POSIXlt object that is then

I want to find the DOY (Day of Year) of some dates. I think to substract the date 1. January from the data to achive this. Something like: > d <- as.Date("2006-03-13") - as.Date("2006-01-01") +1 > d Time difference of 72 days So far so good. But d is a 'difftime' object. How do I get an Integer value from that? I tried severel things, incuding the

I am having a series of problems using date time data that has been converted into a POSIXt and POSIXlt classes. I have hourly time series data from 1900 that has been converted from text data. I assume most of my problems come from a mis-underdanding of the POSIX class. My matrix named (aa) for this year is approx 8700 by 4. When I try to calculate the length of posit column ( which is the

I'm having problems entering dates and times around when daylight savings time starts. If I type (on R 1.8.1 on Gentoo Linux) > ISOdatetime(2004,4,4,0:4,0,0,"GMT") [1] "2004-04-03 19:00:00 EST" "2004-04-03 20:00:00 EST" [3] "2004-04-03 22:00:00 EST" "2004-04-03 22:00:00 EST" [5] "2004-04-03 23:00:00 EST" Giving the times

I am trying to extract only the winters (defined to be 01-Dec through 28-Feb) of daily data from 1948-2002. There are 90 days in each winter season. I wrote the following code to gather the winter dates into a single vector: DJF <- NULL for(year in 1949:1999) { temp.begin <- strptime(paste("01/12", year-1, sep="/"), "%d/%m/%Y") temp.end <-

Hi, Does anybody know why get I this kind of strange situation: Browse[2]> hcEnd [1] "2009-03-29 06:30:00" Browse[2]> class(hcEnd) [1] "POSIXlt" "POSIXt" Browse[2]> is.na(hcEnd) [1] TRUE This issue is the source of my all issues in my program, Thanks for your help -- View this message in context:

Hello, I at first thought this was a system or locale issue, but since it occurs on both Windows and Linux and only for 2004 (AFAIK) I report it. I have a problem with as.POSIXct for the hour between "2004-10-03 02:00:00 GMT" and "2004-10-03 02:59:59 GMT". In short, the 2 AM (GMT) hour in 2004 (but not in other years) is interpreted as 1 AM by strptime: (I use ISOdatetime

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

I was surprised when seq.POSIXt() returned a single value rather than a vector, from inputs that I thought were reasonable. Here's an example to illustrate: > t0 <- ISOdatetime(2002,6,24,0,0,10) ## expected a sequence of 16 times 1 second apart > seq.POSIXt(from=t0,to=t0+15,by='1 sec') [1] "2002-06-24 00:00:10 PDT" ## traces to this call >

Hello, I searched the archives but could not come to a solution. I have to two columns of information t_start_cdt looks like: > t_start_cdt[1:4] [1] "2003-07-09 11:02:25" "2003-07-09 11:10:25" "2003-07-09 11:30:25" [4] "2003-07-09 12:00:25" > class(t_start_cdt) [1] "POSIXt" "POSIXlt" t_end_cdt looks like: > t_end_cdt[1:4]

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

On my new Dell system, it's got a cardreader. More to the point, it's got an idiot menu key... *right* next to the right control key, and just where the annoying keyboard design has it cut down from the oversize space bar ASCII art <ctrl><WinDoze> <tall[ ]<tall<tall<tall <ctrl> Alt>[ tall spacebar ] alt> Win>

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

# pure replication code at end > # These work > > Sys.time() + NA [1] NA > as.POSIXlt(Sys.time(), "GMT") + NA [1] NA > > class(Sys.time() + NA) [1] "POSIXt" "POSIXct" > class(as.POSIXlt(Sys.time(), "GMT") + NA) [1] "POSIXt" "POSIXct" > > x <- Sys.time() + NA > y <- as.POSIXlt(Sys.time(),

When I try to do linear interpolation between financial contracts with maturities on different dates in different months I have come across some behavior I haven't seen before. I have a data frame in R which is loaded from an access database so I can't provide a working example. It was loaded using this code: > dbPath <- "H:/pathToDB/DB.mdb" > channel <-

Hi, Matplot works with x being Date class but not POSIXt. Here is the example with R version 2.5.0 Under development (unstable) (2006-12-06 r40129) Example: x <- Sys.Date() - c(1:10) y <- cbind(1:10, 10:1) class(x) ## [1] "Date" matplot(x, y) x <- strptime(as.character(x), format="%Y-%m-%d") ## [1] "POSIXt" "POSIXlt" matplot(x, y) Error in

Under R-2.2.1, a POSIXlt date created with "strptime" has an unknown Daylight Savings Time flag: > strptime(20051208, "%Y%m%d")$isdst [1] -1 This is true on both Linux (details below) and Windows. It did not occur under R-2.1.0. Any ideas? TIA! > Sys.getenv("TZ") TZ "" Version: platform = i686-pc-linux-gnu arch = i686 os = linux-gnu