similar to: Accessing date subfields

Hello, I do some computations on datasets that come from climate models. These data are huge arrays, significantly larger than typically available RAM, so they have to be accessed row-by-row, or rather slice-by slice, depending on the task. I would like to make an R package to easily access such datasets within R. The C++ backend is ready and being used under Windows/.Net/Visual Basic, but I have

Dear all, I import my data from a csv-file containing one row with date-entries. How can I tell R to treat this data as dates? I've tried to bring it in character-format (as.charachter()) followed by as.POSIXlt() but I get an error message, that the character string is not in a standard unambiguous format, although the date is of format yyyy-mm-dd (what is standard format according to R

Emil et al., On Mon, Jun 11, 2018 at 1:08 AM, Emil Bode <emil.bode at dans.knaw.nl> wrote: > I don't think there's much wrong with is.na(as_date(Inf, > origin='1970-01-01'))==FALSE, as there still is some "non-NA-ness" about > the value (as difftime shows), but that the output when printing is > confusing. The way cat is treating it is clearer: it

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

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I've always found the chron library to be useful for tasks like this: > x <- round(runif(10)*100000, digits=0) > y <- as.Date(x, origin="1970-01-01") > library(chron) > days(y) [1] 7 25 26 25 10 24 1 31 12 8 31 Levels: 1 < 2 < 3 < 4 < 5 < 6 < 7 < 8 < 9 < 10 < 11 < 12 < 13 < ... < 31 Notice that it returns the days as

And now I've seen I copied the wrong part of ?is.na > The default method for is.na applied to an atomic vector returns a logical vector of the same length as its argument x, containing TRUE for those elements marked NA or, for numeric or complex vectors, NaN, and FALSE otherwise. Key point being "atomic vector" here. On Sat, Jun 9, 2018 at 1:41 PM, Joris Meys <jorismeys at

Hello I have this little dataset, my goal is create one column in the data.frame with between the diference DataTime and Duration. I'm using the next code to make do this TIME_STAMP SESSIONTIME Time TimeStart 1162343932 8320 2006-10-31 19:01:34 2006-10-31 16:42:54 1162343215 592 2006-10-31 19:02:04 2006-10-31 18:52:12 1162341465 11875

Dear All, I'm trying to use dynlm to fit a time series. I have 3 seasonal terms. Here is an example of the problem. This is my time variable, hourly data: timeSeries <- seq(as.POSIXct("2011-01-01 00:00:00"), as.POSIXct("2011-12-31 23:00:00"), by="hour") My response is: y <- rnorm(length(t), 1000, 500) There are 3 seasonal factors: t.h <-

Hola a todos: Debe de ser una tontería, pero no consigo saber porque la siguiente linea no devuelve la fecha actual: as.Date(as.numeric(Sys.time())) He hecho esa prueba porque no consigo pasar un numero convertido a partir de una fecha y modificado a fecha de nuevo. Gracias por adelantado. Un saludo, Alberto. [[alternative HTML version deleted]]

Hello R wizards, What is the best way to read a data file containing both fixed-width and tab-delimited files? (More detail follows.) _*Details:*_ The U.S. Bureau of Labor Statistics provides local area unemployment statistics at ftp://ftp.bls.gov/pub/time.series/la/, and the data are documented in the file la.txt <ftp://ftp.bls.gov/pub/time.series/la/la.txt>. Each data file has five

Dear R users, I am currently working in subsetting a zooreg() object using either window or subset. I have a solution but it may be a bit cumbersome when I start working with actual data. Your inputs would be greatly appreciated. Example: I have a zooreg() object that starts in 1997 and ends in 2001. This object contains daily data for the 4 years

Indeed. as_date is from lubridate, but the same holds for as.Date. The output and it's interpretation should be consistent, otherwise it leads to confusion when programming. I understand that the difference exists after asking a question on Stack Overflow: https://stackoverflow.com/q/50766089/914686 This understanding is never mentioned in the documentation - that an Inf date is actually

Apparently, as.POSIXlt takes one o'clock as the start of the day : > as.POSIXlt(0,origin="1970-01-01") [1] "1970-01-01 01:00:00 CET" > as.POSIXlt(0,origin="1970-01-01 00:00:00") [1] "1970-01-01 01:00:00 CET" > as.POSIXlt(0,origin="1970-01-01 23:59:59") [1] "1970-01-02 00:59:59 CET" Cheers -- Joris Meys Statistical

the date were created with chron with this argument format=c(dates="Y/m/d", times="H:M:S")) so I have the dates being displayed as (10/06/22 12:00:00) I would like to have them displayed as "2010-06-22 12:00:00" or "%Y-%m-%d %H:%M:%S" and then I can convert these for mergeing with another data frame x <- (structure(c(14464, 14464.0104166667,

I tried the code that Richard O'Keefe posted last week, to wit: library(chron) ymd.to.POSIXlt <- function (y, m, d) as.POSIXlt(chron(julian(y=y, x=m, d=d))) n <- 100000 y <- sample(1970:2004, n, replace=TRUE) m <- sample(1:12, n, replace=TRUE) d <- sample(1:28, n, replace=TRUE) system.time(ymd.to.POSIXlt(y, m, d)) [1] 8.78 0.10

Dear list, When using as.POSIXlt with times measured down to microseconds the default format.POSIXlt seems to cause some possibly undesirable behaviour: According to the code in format.POSIXlt the maximum accuracy of printing fractional seconds is 1 microsecond, but if I do; options( digits.secs = 6 ) as.POSIXlt( 1.000002 , tz="", origin="1970-01-01") as.POSIXlt( 1.999998 ,

The interface for dates in R is a little confusing to me. I want to create a vector of Date objects from vectors of years, months, and days. One solution I found is: years <- c(1991, 1992) months <- c(1, 10) days <- c(1, 2) dates <- as.Date(ISOdate(years, months, days)) But, in this solution the ISOdate function converts the vectors into characters, which can cause serious

Hi, I am trying to assign "Season" values to dates depending on when they occur. For example, the following dates would be assigned the following "Season" numbers based on the "season" intervals detailed below in the code: ddate Season 29/12/1998 20:00:33 1 02/01/1999 05:20:44 2 02/01/1999 06:18:36 2 02/02/1999

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 <-