similar to: Creating a new factor from other factors and a date range

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

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

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

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),

The most important thing is that Date objects by definition do not include time of day. You want to look at ISOdatetime() and as.POSIXct() instead. And beware daylight savings time issues. -pd On 18 Apr 2016, at 15:09 , Ogbos Okike <giftedlife2014 at gmail.com> wrote: > Dear All, > > I have a data set containing year, month, day and counts as shown below: > data <-

Dear All, Many thanks for bailing me out. Ogbos On Apr 18, 2016 9:07 PM, "David Winsemius" <dwinsemius at comcast.net> wrote: > > > On Apr 18, 2016, at 10:44 AM, Ogbos Okike <giftedlife2014 at gmail.com> > wrote: > > > > Dear ALL, > > Thank you so much for your contributions. > > I have made some progress. Below is a simple script I

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

Dear ALL, Thank you so much for your contributions. I have made some progress. Below is a simple script I gleaned from your kind responses: Sys.setenv(TZ="Etc/GMT") dates <- c("02/27/92", "02/27/92", "01/14/92", "02/28/92", "02/01/92") times <- c("23:0:0", "22:0:0", "01:00:00", "18:0:0",

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

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

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

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)

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),

Hello R-experts! I am using R Version 1.7.1 (2003-06-16) on a Debian Linux box and I have discovered an odd result when plotting data involving dates. Please try this minimal example: a = seq(ISOdate(2000,1,1), ISOdate(2001,1,1), "months") b = 1:13 plot(a,b, col="red") What I get is a plot that looks as expected except the x-axis is mostly red. Can anyone reproduce this

Thanks for this clarification. I have learned in the meantime that it is necessary to be very careful when using all these POSIX things. As another example, here is something that made me scratch my head just yesterday: When I create a sequence of days that happens to start before and ends in daylight savings time, I seem to lose a day: > seq(from = strptime("20030329",

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

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]

Hi, I am trying to create a googleVis motion chart with monthly data. When formatting the date column as a Date class variable, the plot as presented in the browser becomes considerably slower and very prone to crashing the browser. To illustrate this issue I have modified the WorldBank demo. ### objects from demo("WorldBank", package = "googleVis") M <-

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

Hello, I have an x, y data set of circa 966 points, and counting, where I am trying to plot one integer y-axis number per a corresponding x-axis date, in R. The command plot(initialPlot$Dates, initialPlot$AxisData), where $Dates is 2007-07-24:2010-03-15, and $AxisData is the corresponding y coordinates, results in an accurate x-axis, but unusable plot, as lines and points are not generated, only