[R] Extracting day of month from Date objects

[Phil Spector]

I've always found the chron library to be useful for
tasks like this:

> x <- round(runif(10)*100000, digits=0)
> y <- as.Date(x, origin="1970-01-01")
> library(chron)
> days(y)
  [1] 7  25 26 25 10 24 1  31 12 8 
31 Levels: 1 < 2 < 3 < 4 < 5 < 6 < 7 < 8 < 9 < 10 < 11 < 12 < 13 < ... < 31

Notice that it returns the days as factors.

 					- Phil Spector
 					 Statistical Computing Facility
 					 Department of Statistics
 					 UC Berkeley

On May 24, 2011, at 10:19 AM, Kang Min wrote:

> I have another question -
>
> I'd like to extract dates from a vector of yyyy-mm-dd, so I just want
> the dd.
>
> x <- round(runif(10)*100000, digits=0)
> y <- as.Date(x, origin="1970-01-01")
>
> I tried this based on the code that Jim provided, but it just printed
> the whole date. I think I just need to tweak it a little, but haven't
> been able to figure it out.