[R] How to transform the date format as "20050425"

[Chris Evans]

On 25 Apr 2005 at 15:18, Yong Wang wrote:

> Dear R user,
> if the dates are in format as "20050425" i.e., Apr. 25 2004"
> can you suggest an easy way to transfom it to standard form
> as "2005-04-25" or "2004Apr25" or "2005/04/25" or any other
> format which is R recognizable?
> if there is no easy way to do that, can you let me know what
> is the function in R performing similiar function as the "string"
> function in C or some other more basic language, so I can loop through
> all dates to make the desired change. thank you regards
> 
If the format really is always like that you can use this:
require(date) # gives you date handling
x <- as.character(20050425)
date <- 
mdy.date(as.numeric(substr(x,5,6)),as.numeric(substr(x,7,8)),\ 
as.numeric(substr(x,1,4)))

(You'll have to remove the line wrapping there, the "\" is where I 
put a break in!)

Good luck!

Chris

-- 
Chris Evans <chris at psyctc.org>
Consultant Psychiatrist in Psychotherapy, Rampton Hospital; 
Research Programmes Director, Nottinghamshire NHS Trust, 
Hon. SL Institute of Psychiatry
*** My views are my own and not representative of those institutions 
***