similar to: Processing calendar dates with R

Displaying 20 results from an estimated 1000 matches similar to: "Processing calendar dates with R"

2003 Nov 26
6
FDA and ICH Compliance of R
Does anybody know if R is FDA or ICH (or EMEA...) compliant? AFAIK S-Plus is but that means nothing... -- Trebate bolji pristup internetu? Nazovite IskonInternet na 0800 1000 ili pogledajte http://www.iskon.biz/individualni/usluge/dialup/
2007 Mar 22
2
difftime / RBloomberg
hi, I've troubles with some difftime objects. e.g. ISOdate(2001, 4, 26) - ISOdate(2001, 2, 26) - 2 works, telling me "Time difference of 57 days". But when I'd like to add days, such as ISOdate(2001, 4, 26) - ISOdate(2001, 2, 26) + 2 the function gives me an error. Function "as.COMDate.chron" of the Rbloomberg package doesn't work for that reason. I'm
2003 Apr 27
2
Basic date time arithmetics operations
Hello, For basic date time arithmetics operations, AFAK, there're actually the function difftime() and the (dt + num) operations. I'm wondering if other basic operations exist, like add(dt, num, unit) where unit would be "y", "q", "m", etc. Also for the function seq.dates (or seq.POSIXt), the case for by="months" would be more useful if it
2003 Apr 27
2
Basic date time arithmetics operations
Hello, For basic date time arithmetics operations, AFAK, there're actually the function difftime() and the (dt + num) operations. I'm wondering if other basic operations exist, like add(dt, num, unit) where unit would be "y", "q", "m", etc. Also for the function seq.dates (or seq.POSIXt), the case for by="months" would be more useful if it
2004 Aug 19
2
proposed change to [.POSIXct
R developers, The "tzone" attribute is stripped from a POSIXct object when the subscript command is called ("[.POISXct"). This results in dates being printed in the locale specific format after a subscript operation is applied to a POSIXct object which has cause several problems for me in the past. Here is an example of this problem under R 1.9.1: > x <-
2010 Apr 29
1
image function with date-time on X axis
I am trying to plot a image where the x axis has the units of time. When I issue the image(x,y,z) command with x as a POSIXct object, it fails to put a time stamp on the x axis. Instead I get a warning "Incompatible methods" warning and no dates on my x axis. This example shows my problem: Rmat=t(matrix(data=rnorm(1:500),ncol=10,nrow=50)) tax=seq(ISOdate(2010,4,14,12,0,0),
2002 Oct 17
4
Posix Problem, difftime
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
2009 Dec 11
1
Calendar week ISO (PR#14132)
Hi there =20 I use Gnu R sometimes at work.=20 =20 Unfortunately we use Windows and R has problems with getting the calendar week number with the first week as the one which has at least 4 days. A colleague told me that he has the same problem.=20 =20 Below you can see what I use now, for finding the right week.=20 =20 =20 Kind regards,=20 Samuel Andreas Meichtry =20 =20
2003 Nov 19
5
ISOdate returns incorrect date?
Dear all, I have found the following (for me) incomprehensible behaviour of ISOdate (POSIXct): > ISOdate(1900,6,16) [1] "1900-06-15 14:00:00 Westeurop?ische Sommerzeit" > ISOdate(1950,6,16) [1] "1950-06-16 14:00:00 Westeurop?ische Sommerzeit" Note that in the first case I get the 15th of June back, not the 16th as I would have expected! This happened under R-1.7.1 on
2003 Nov 14
5
ISOdate() and strptime()
Dear R-people! I am using R 1.8.0, under Windows XP. While using ISOdate() and strptime(), I noticed the following behaviour when "wrong" arguments (e.g., months>12) are given to these functions: > ISOdate(year=2003,month=2,day=20) #ok [1] "2003-02-20 13:00:00 Westeurop?ische Normalzeit" > ISOdate(year=2003,month=2,day=30) #wrong day, but returns a value [1]
2007 May 10
3
Getting the last day of the month.
Hi, Given a date, how do I get the last date of that month? I have data in the form YYYYMM, that I've read as a date using > x$Date <- as.Date(ISOdate(substr(x$YearEnd,1,4),substr(x$YearEnd,5,6),1)) But this gives the first day of the month. To get the last day of the month, I tried > as.Date(as.yearmon(x$Date,frac=0)) But I don't get the last day of the month here. (Tried
2002 May 21
1
I() fails on objects of class POSIXct (PR#1587)
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
2006 Apr 10
3
timeAlign
I use POSIXct for datetimes. Is thee a timeAlign function that I can use where : align by year direction -1 ==> start of this year direction 1 ==> start of next year align by week direction -1 ==> date on last sunday direction 1 ==> date on next sunday align by day direction -1 ==> time at past midnight direction 1 ==> time at this comming
2018 Jan 22
2
Manipulating two large dataset differing by date and time
Dear Members, Compliments of the Season!! Below is a part of a code I use for Fourier analysis of signals. The code handles data with the format 05 01 01 8628 (year, month, day and count) 05 01 02 8589 (year, month, day and count) The sample data is attached as 2005daily.txt. I would like to adapt the code to handle data of the form: 05 01 01 00 4009
2002 May 28
2
histogramming dates
I'd like to make a plot showing frequency of an event. The data is in a data from that includes Year, Month and Day (of month) fields, so I created a Date with ISOdate(Year, Month, Day, tz=''). I can plot frequencies for the year 2002 with > thisyear <- Date[Year==2002] > hist( thisyear, xaxt='n' ) > axis.POSIXct( 1, at=seq(min(thisyear), max(thisyear),
2003 Sep 12
2
Sorting a vector by date
Hello out there.... Again I have a problem and I stuck... How can I sort a vector of dates? For example I have the vector a<-ISOdate(2001, 1, 1) + 70*86400*runif(10) How can this vector be sorted chronological? And what's the function I should work with to handle these entries? (in sense of: which(a>2001-01-04) or somehting like that) Thank you for helping M.Kirschbaum
2004 Nov 03
3
cut POSIX results in NA - bug?
Dear all I try to make hourly average by cut() function, which almost works as *I* expected. What puzled me is that if there is only one item at the end of your data it results in NA. Example will explain what I mean datum<-seq(ISOdate(2004,8,31), ISOdate(2004,9,1), "min") cut(datum[1370:1381],"hour", labels=F) [1] 1 1 1 1 1 1 1 1 1 1 1 NA
2003 Apr 30
2
ylab in plot.POSIXct
I am using R-1.7.0 and have some data which consist of one vector of numbers and a second corresponding vector of dates belonging to the POSIXct class. I would like to plot the numbers against the dates. What is the best way to do this? It almost works to just call `plot.' However if I do this while using the `ylab' parameter I get a warning message: parameter "ylab"
2016 Apr 18
4
as.Date
Dear All, I have a data set containing year, month, day and counts as shown below: data <- read.table("data.txt", col.names = c("year", "month", "day", "counts")) Using the formula below, I converted the data to as date and plotted. new.century <- data$year < 70 data$year <- ifelse(new.century, data$year + 2000, data$year + 1900)
2018 Jan 22
0
Manipulating two large dataset differing by date and time
Hi Ogbos, You can just use ISOdate. If you pass more values, it will process them: ISOdate(2018,01,22) [1] "2018-01-22 12:00:00 GMT" > ISOdate(2018,01,22,18,17) [1] "2018-01-22 18:17:00 GMT" Add something like: if(is.null(data$hour),data$hour<-12 then pass data$hour as it will default to the same value as if you hadn't passed it. Jim On Mon, Jan 22, 2018 at 6:01