similar to: Quirks with system.time and simulations

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

I know this: > library(date) > x="1979-04-04" > try=as.date(x, "ymd") > print(try) [1] 4Apr79 and that `x' here has to be a string, e.g.: > x=1979-04-04 > print(x) [1] 1971 I'm stuck in reading from a file. I say: > A <- read.table(file="try") > print(A) V1 V2 1 1979-04-04

Hi! Is not there an standard R function to retrieve the day of the year (since 1st Jan of the same year)? I know I can make my own using julian, but find it weird that having days(), months() etc doy() does not exist as an standard function. Also, is the following not a bit inconsistent? > a <- chron("20100506",format="ymd") > a [1] 100506 > years(a) [1] 2010

Dear R users, Given this data: x <- seq(1,100,1) dx <- as.POSIXct(x*900, origin="2007-06-01 00:00:00") dfx <- data.frame(dx) Now to play around for example: subset(dfx, dx > as.POSIXct("2007-06-01 16:00:00")) Ok. Now for some reason I want to extract the datapoints between hours 10:00:00 and 14:00:00, so I thought well: subset(dfx, dx >

Full_Name: Alec Stephenson Version: 1.6.0 OS: linux Submission from: (NULL) (148.88.138.5) Appears to be a sign error in as.POSIX(lt/ct) > library("chron") The following is fine, with default origin. > tmp <- chron(1:2, origin = c(1,1,1970)) > as.POSIXlt(tmp) [1] "1970-01-02 01:00:00 GMT" "1970-01-03 01:00:00 GMT" These are not. > tmp <-

Dear all, I have a problem with the function Julian, may be a bug in the function ? Here is a vector of character, which represents dates (May 18 to May 20 2000): > amj <- c("2000-05-18","2000-05-18","2000-05-18","2000-05-19","2000-05-19" > ,"2000-05-19", "2000-05-19", "2000-05-20", "2000-05-20",

Dear, According to the documentation, the parameters given in "dates" are passed to the function "chron". When trying this out, it turns out that this apparently doesn't happen, eg: > dates("20100101",format="Ymd",out.format="day mon year") [1] 01/01/10 > chron("20100101",format="Ymd",out.format="day mon

How do I parse a date "yyyymmdd"? I tried asking chron(s, "ymd") but that didn't work. Would the date parsing routines of the Date class of 1.9 grok this? -- Ajay Shah Consultant ajayshah at mayin.org Department of Economic Affairs http://www.mayin.org/ajayshah Ministry of Finance, New Delhi

Agradezco la ayuda recibida me vino muy bien,,, el problema de instalar el paquete lubridate es que no está en los repositorios de Debian,,, al usar RStudio creo que se debe instalar en ~/R/x86_64-pc-linux-gnu-library previa compilación de fuente bajada de r-cran,,, cosa que será otro pedido de ayuda en el futuro si sale mal,,, Saludos Horacio El día 30 de diciembre de 2016, 7:05, Carlos Ortega

Hi, how it's possible to extract the year and the number of days from Julian date. i'm little confused about the last two functions and ?years . EDATE comes from sqlQuery with as.is=T EDATE <- as.POSIXlt(datvears$ENROLLDAY) Many thanks, Christian > EDATE[1:5] [1] "2000-06-30 11:25:01" "2000-06-30 11:39:55" "2000-06-30 12:11:11" [4]

I have date data as a numeric and hourly data in 0 to 2300 hours in a dataframe. d <- rep(20110101,24) h <- seq(from = 0, to = 2300, by = 100) df <- data.frame(LST_DATE = d, LST_TIME = h, data = rnorm(24, 0, 1)) S <- chron(dates. = as.character(df$LST_DATE), times. = paste(as.character(df$LST_TIME/100), ":0:0", sep = ""), format =

I'm trying to read intraday zoo but running into issues (again) ... what am I missing here? (the date doesn't seem to read in correctly) > head(dat) TrdDate TrdTime impliedVol 1 20090102 09:55:03 0.3610715 2 20090102 09:55:04 0.3637943 3 20090102 09:55:05 0.3752375 4 20090102 09:55:05 0.4190025 5 20090102 09:55:06 0.3696080 6 20090102 09:55:06 0.4944981 > f <-

I have a daily time series and have two questions to get some help with. Firs,t I have dates in simple numeric values. e.g. ymd [1] 20050104 20050105 20050106 20050107 20050110 20050111 20050113 20050114 [9] 20050118 20050120 20050121 20050124 20050125 20050126 20050127 20050128 [17] 20050201 20050202 20050203 20050204 Now, I'd like to compute statistics, e.g. acf, by business days. So, I

How can I extract only the time component from an POSIXlt object? For example if I try the following it still returns both the date and time... >as.POSIXlt(tr.date[1]) [1] "2010-10-18 21:46:53" >as.POSIXlt(tr.date[1],"%H:%M:%S") [1] "2010-10-18 21:46:53" round and trunc don't help... is there an "as.Time" equivalent to as.Date ? Thanks,

Hey R folks, i found some strange (to me) behaviour with chron to POSIXct conversion. The two lines of code result in two different results, on ewith the correct time zone, one without: library(chron) as.POSIXct(chron('12/12/2000'), tz = 'UTC') as.POSIXlt(chron('12/12/2000'), tz = 'UTC') Only the code below would give me a POSIXct object with the correct time

Dear all, I have several text files looking like this: 9063032 19700201 22:00 174.067 9063032 19700201 23:00 174.076 9063032 19700202 00:00 174.085 9063032 19700202 01:00 174.091 9063032 19700202 02:00 174.094 9063032 19700202 03:00 174.091 9063032 19700202 04:00 174.082 9063032 19700202 05:00 174.079 And I run this loop: for (j in 1:nr.of.files) { #Import: DF <-

hello, I have a vector of factors > str(rcptdt) Factor w/ 51 levels "1/10/03","1/13/03",..: > length(rcptdt) [1] 87 which i want to convert to class POSIXlt to extract the day, so: a1<-format(rcptdt,"%m/%d/%y") > length(a1) [1] 87 and: a2<-strptime(a1, "%m/%d/%y") str(a2) `POSIXlt', format: chr [1:87] "2002-04-18"

Hi R users, I have a maybe small problem which I cannot solve by myself. I want to convert "chron" "dates" "times" (04/30/06 11:35:00) to a number with as.POSIXct. The Problem is that I can't choose different timezones. I always get "CEST" and not "UTC" what I need. date = as.POSIXct(y,tz="UTC") "2006-04-30 11:35:00

Full_Name: Arni Magnusson Version: 1.6.2 OS: Windows XP Submission from: (NULL) (210.48.49.68) Hi there. I'm experiencing unexpected behaviour from as.POSIXct: > as.POSIXct("1969-12-24") [1] "1969-12-23 23:00:00 New Zealand Standard Time" > as.POSIXlt("1969-12-24") [1] "1969-12-24" > as.POSIXlt("1969-12-24")+1 [1] "1969-12-23

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