[R] retaining formatting when converting a vector to a matrix/data.frame?

[jim holtman]

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 <thomas.pujol at yahoo.com> 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 at 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?