[R] 'Date' elements within a matrix

[Phil Spector]

It will be difficult or impossible to store objects of
class Date in a matrix -- you'll need to store them
in a data frame:

> pts = seq(as.Date("2011-01-01"), as.Date("2011-01-09"), by="1 day")
> z = data.frame(pts[1:3],pts[4:6],pts[7:9])
> z
     pts.1.3.   pts.4.6.   pts.7.9.
1 2011-01-01 2011-01-04 2011-01-07
2 2011-01-02 2011-01-05 2011-01-08
3 2011-01-03 2011-01-06 2011-01-09
> sapply(z,class)
pts.1.3. pts.4.6. pts.7.9.
   "Date"   "Date"   "Date"


 					- Phil Spector
 					 Statistical Computing Facility
 					 Department of Statistics
 					 UC Berkeley
 					 spector at stat.berkeley.edu


On Sat, 12 Mar 2011, Bogaso Christofer wrote:

> Dear all, when I put date objects (class of 'Date') in a matrix it becomes
> numeric:
>
>> dat <- matrix(seq(as.Date("2011-01-01"), as.Date("2011-01-09"), by="1
> day"), 3)
>
>> dat
>
>      [,1]  [,2]  [,3]
>
> [1,] 14975 14978 14981
>
> [2,] 14976 14979 14982
>
> [3,] 14977 14980 14983
>
>> class(dat[1,1])
>
> [1] "numeric"
>
>
>
> As it could not preserve the 'Date' characteristics after putting my Date
> observations, I find it difficult to carry forward further calculation with
> Dates. Can somebody help me on how to preserve the Data properties while
> storing them within some matrix?
>
>
>
> Thanks
>
>
> 	[[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.
>