similar to: Casting "character" to "Date" using the "as" function

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(

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

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 <-

Full_Name: Suharto Anggono Version: 2.8.1 OS: Windows Submission from: (NULL) (125.161.134.206) About PR#14067, now I understand why (Date + difftime) does not use '+.Date'. But, before I understand, it was surprising. The surprise is also reflected in the post "Problem with +(POSIXt, difftime) dispatching -- WAS: How to create sequence of constant time interval" in R-help

Good evening all, This topic is gone into at a bit more length at my related Stack Overflow question here: http://stackoverflow.com/questions/34647674/why-do-as-methods-remove-vector-names-and-is-there-a-way-around-it There are two lingering issues despite the abundant insight received at SO, namely: 1) _Why_ do as methods remove their arguments' names attribute? This is a fact which is

The following code: cut(as.POSIXct("2009-11-01 04:00:00", tz="America/Los_Angeles"), "1 day") gives the error: Error in seq.int(0, to - from, by) : 'to' must be finite This is related to November 1st, 2009 being the switchover date from daylight savings time to standard time in the America/Los_Angeles time zone. In particular, in cut.POSIXt, the starting

# 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(),

Hello! na.encode does not have any effect on format of NA values of Date and POSIXct (POSIXlt?) "atomic" classes in a data.frame. Here is the example (the same in R 2.3.1 and 2.5.0 (2006-09-19 r39409)): testData <- data.frame(num=c(NA, 2.6), int=c(1, NA), fac=factor(c(NA, "abc")), cha=c("a",

I have found what looks like a small problem in trunc.POSIXt() involving the transition to/from standard time and daylight savings time. Assuming my assessment is correct, I have a potential solution to offer. If a time in daylight savings time is rounded such that the rounded value is on the other side of the transition, the isdst element does not get changed accordingly. I have tested only

Dear all, I hope this is a right place to post this; r-help might be appropriate but it looks like I'm suggesting a change in base package, so I decided to post here. (+ Apologies if that has been changed recently -- the version I'm using is R.2.12.2 on Windows.) I've noticed an unexpected behavior of trunc.POSIXt: foo <- seq(as.POSIXct( "2009-10-23 22:00:00"),

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

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]

I have asked this question before, and received some suggestions for work-arounds that get the job done--and they are much appreciated. But I would still like to find out if I'm missing something, and whether there is a direct way using POSIXt functions (as.POSIXct, as.POSIXlt, strptime, in particular). I have environmental data collected once per minute. Here is a subset of 3 input

Hi, I'm working with objects of classes "Date","POSIXlt" and "POSIXct" and still having some Date/Time-related concepts unclear. In the documentation of "as.Date" one can find: "The 'as.Date' methods accept ... '"POSIXlt"' and '"POSIXct"'. (The last are converted to days by ignoring the time after

Would it make sense for as.Date.POSIXct to not assume tz="UTC" if the POSIXct object has a valid tzone attribute? Current behavior may be confusing in certain cases, for example: > (d <- structure(1090450800, tzone="Europe/Berlin", + class=c("POSIXct","POSIXt"))) [1] "2004-07-22 01:00:00 CEST" > as.Date(d) [1] "2004-07-21" >

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

For certain values, round.POSIXt(tm,'day') does not round to midnight as documented. The reason is that trunc.POSIXt() does not adjust the value of the isdst element. Assuming my assessment of the reason is correct, I have a potential solution to offer. Additional discussion is in bug report #1543. -Don > x <- c(as.POSIXct('2001-4-1 3:15'),as.POSIXct('2001-5-2

Thank you, Jskud. I can reproduce your problem, though not the seg.fault, see below >>>>> "Jskud" == Jskud <Jskud@Jskud.com> >>>>> on Sat, 30 Apr 2005 09:04:03 +0200 (CEST) writes: Jskud> In attempting to build R using rpmbuild --rebuild Jskud> R-2.1.0-0.fdr.2.fc3.src.rpm Jskud> on a fairly up-to-date RedHat 9 system (that

I am finding that axis.POSIXct uses the local timezone for deciding where to put tic marks, even if the data being plotted are in another time zone. The solution is to use attr() to copy from the 'x' (provided as an argument) to the 'z' (used for the 'at' locations). I have pasted my proposed solution in section 1 below (as a diff). Then, in section 2, I'll put some

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,