Here is a function that I use since the numeric value is the number of seconds from 1/1/1970, which is the Unix time base that I am also using:
unix2POSIXct <- function (time) structure(time, class = c("POSIXt", "POSIXct")) It just reassigns the proper class. On Jan 3, 2008 12:01 PM, Thomas Pujol <[EMAIL PROTECTED]> wrote: > Please see example code below. > > I have a vector ("mydata") of length 10. "mydata" can have various formats > (e.g. numeric, text, POSIXct, etc) I use the matrix and data.frame functions > to convert "mydata" to a dataframe ("mydf") of 2 columns and 5 rows. > > What is a "good" way to ensure that the format is retained when I create the > data.frame? > Currently, data in the "POSIXct" format is converted to numeric. > > Also, for my edification, is there a "good" way to convert numeric values > such as these back to the original "POSIXct" format/values? > > Much thanks! > > #here I lose the "POSIXct" formatting > > mydata <- rep(Sys.time(), 10) > str(mydata) > mydf <- data.frame(matrix(data=mydata, nrow=5, ncol=2)) > str(mydf) > > #here using only "matrix" I also lose the "POSIXct" formatting > > mydata <- rep(Sys.time(), 10) > str(mydata) > mydf <- matrix(data=mydata, nrow=5, ncol=2) > str(mydf) > > > #this works as intended > mydata <- rep(1:10) > str(mydata) > mydf <- data.frame(matrix(data=mydata, nrow=5, ncol=2)) > str(mydf) > > > > --------------------------------- > > [[alternative HTML version deleted]] > > ______________________________________________ > R-help@r-project.org mailing list > https://stat.ethz.ch/mailman/listinfo/r-help > PLEASE do read the posting guide http://www.R-project.org/posting-guide.html > and provide commented, minimal, self-contained, reproducible code. > -- Jim Holtman Cincinnati, OH +1 513 646 9390 What is the problem you are trying to solve? ______________________________________________ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.