similar to: FW: is.weekend() odd behaviour

It seems is.weekend() is unsure ? # Start R 1.9.0 with --vanilla on windows xp # load package chron > table(is.weekend(sapply(1:100, function(i){Sys.sleep(0.05);Sys.time()}))) FALSE TRUE 68 32 > date() [1] "Wed May 26 11:18:56 2004" > version _ platform i386-pc-mingw32 arch i386 os mingw32 system i386, mingw32

Hello, I have a dataset which has fields giving both calendar date and weekday. I know better functions are now available, but I am still using chron because of the is.holiday() function and a homemade (even Heath Robinson would be ashamed) is.daylight() function. As a check for typos in the data input, I checked that the dates matched the weekdays. I'm getting some confusing results

2017-06-22 20:31 GMT+02:00 Uwe Ligges <ligges at statistik.tu-dortmund.de>: > > > On 22.06.2017 20:09, I?aki ?car wrote: >> >> 2017-06-22 19:49 GMT+02:00 Uwe Ligges <ligges at statistik.tu-dortmund.de>: >>> >>> On 22.06.2017 17:11, Bernd Funovits wrote: >>>> >>>> >>>> Hello, >>>> >>>> I

Hi, Please see below for post on r-help regarding data.frame() and the possibility of dropping rownames, for space and time reasons. I've made some changes, attached, and it seems to be working well. I see the expected space (90% saved) and time (10 times faster) savings. There are no doubt some bugs, and needs more work and testing, but I thought I would post first at this stage. Could some

Hello All: I am trying to generate a sequence of dates using library(chron). Using the following code, I got most of what I want, dts <- seq.dates("01/02/1998", "01/10/2001", by="day") dts <- dts[!is.weekend(dts)] a sequence of weekdays only (no weekend dates), with first observation appearing as 01/02/98 and the last 01/10/01. But I would

2017-06-22 19:49 GMT+02:00 Uwe Ligges <ligges at statistik.tu-dortmund.de>: > On 22.06.2017 17:11, Bernd Funovits wrote: >> >> Hello, >> >> I experienced some unexpected behaviour while determining the rank of matrices (sometimes 1x1 matrices): >> base::qr(matrix(1e-20))$rank returns 1 (incorrect) >> base::qr(diag(c(1, 1e-20)))$rank returns 2

On 22.06.2017 20:09, I?aki ?car wrote: > 2017-06-22 19:49 GMT+02:00 Uwe Ligges <ligges at statistik.tu-dortmund.de>: >> On 22.06.2017 17:11, Bernd Funovits wrote: >>> >>> Hello, >>> >>> I experienced some unexpected behaviour while determining the rank of matrices (sometimes 1x1 matrices): >>> base::qr(matrix(1e-20))$rank returns 1

The problem with POSIXt is that you must consider timezones and daylight vs. standard time issues even if you don't want to. This violates modularity (viz. your routines becomes coupled to unrelated information) and leads to subtle errors where different routines are assuming different time zones. The problem is that the time, date, day of the week, month, etc. of a date depend on its

Uwe, You said you used testdata <- data.frame(date = strptime(c("31121991", "31121991"), "%d%m%Y"), nothing = c(NA, NA)) but that's not the same object, and that one does work for me. > dput(testdata) structure(list(date = structure(c(694137600, 694137600), class = c("POSIXt", "POSIXct")), nothing = c(NA, NA)),

Hi, The following function works, but is there a neater way to write it? f = function(x,...) { # return a character vector of the arguments passed in after 'x' gsub(" ","",unlist(strsplit(deparse(substitute(list(...))),"[(,)]")))[-1] } > f(x,a,b,c*d) [1] "a" "b" "c*d" > Thanks. [[alternative HTML

Full_Name: Kem Phillips Version: 2.7.1 (2008-06-23) OS: Windows Xp professional Submission from: (NULL) (98.221.200.108) The Hmisc function describe fails, giving the error message: Error in formatDateTime(dd, atx, !timeUsed) : could not find function "format.dates" Loading the chron package, where function dates apparently resides, does not fix the problem. Note

Hi, One of the big decisions when writing code is how to handle dates and times. Gabor Grothendieck provided an excellent overview of the issue in his R News 4/1 (2004) article, and many users and developers are probably using it as a guide. The proposed guideline is to use the simplest class required; as Gabor put it "use Date if possible, otherwise use chron, and otherwise use

--- On Mon, 1/17/11, Raymond Wong <raywong365@yahoo.ca> wrote: From: Raymond Wong <raywong365@yahoo.ca> Subject: Re: [R] help in calculating ar on ranked vector To: "Uwe Ligges" <ligges@statistik.tu-dortmund.de> Received: Monday, January 17, 2011, 11:56 AM Thanks Uwe:   Here is my code. the first set of print statements work, but not the second.   #

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

Hi All, I am iterating through dated materials, with variable start and end dates, and would like to skip procedures everytime I encounter a weekend or holiday. To do this, I thought the easiest way would be to create a TRUE/FALSE vector corresponding to each day where it is TRUE if a workday, and FALSE if a weekend or holiday. So far I have been able to do this for weekdays: startDate <-

I know that this is correct: library(chron) x = dates("01-03-04", format="d-m-y", out.format="day mon year") print(x) It gives me the string "01 Mar 2004" which is correct. I also know that I can say: print(day.of.week(3,1,2004)) in which case he says 1, for today is monday. My question is: How do I combine these two!? :-) I have a

Hi David, ----- Original Message ----- > From: "David Smith" <davidsmi at microsoft.com> > To: "Dan Tenenbaum" <dtenenba at fredhutch.org>, "Uwe Ligges" <ligges at statistik.tu-dortmund.de>, "Elliot Waingold" > <Elliot.Waingold at microsoft.com> > Cc: "R-devel at r-project.org" <r-devel at r-project.org>

Hi, I am trying to count weekday of the month using R. For example, 1/4/2001 is the 4th weekday of Jan, and 1/5/2001 is the 5th weekday of the month, and 1/8/2001 is the 6th weekday of the month, etc. I get as far as extracting the weekdays from a sequence of dates (see below). But I have not yet figured out a fast way of counting without using a For Loop. Does anyone know how to do such counting

Dear All- I am trying to merge two data files - they have different date formats and different times zones. I need to match up the date/time of the datasets and then invoke a conditional statement, such as: if dataC$mph is >= 12 then keep dataM$co23 for the corresponding time/date stamp. snippets of data files: *dataC.txt* LST in mph Deg DegF DegF2 % volts Deg

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"