[R] HMisc describe -- error with dates

[Gabor Grothendieck]

dates is part of chron.  There may be something wrong in 
Hmisc's detection of chron objects.

> chron(1)
[1] 01/02/70

> isChron(chron(1))
FALSE

---
 
Date: Tue, 11 Nov 2003 20:06:38 -0500 
From: <tmurph6 at po-box.mcgill.ca>
To: Frank E Harrell Jr <feh3k at spamcop.net> 
Cc: <r-help at stat.math.ethz.ch> 
Subject: Re: [R] HMisc describe -- error with dates 

 
 
I am using the chron package. I have no preference for which function I use. I
just want the most reliable format for HMisc functions and general plotting. I
like the ddmonyyy formats (e.g. 11NOV2003). What would you recommend?

Thank you!

Quoting Frank E Harrell Jr <feh3k at spamcop.net>:

> On Tue, 11 Nov 2003 18:28:24 -0500
> tmurph6 at po-box.mcgill.ca wrote:
> 
> > Hello,
> > 
> > I am trying to use HMisc describe on a data frame. I have specified
> > certain variables as dates using, for example:
> > 
> > df1$aidsdate <- dates(aidsdate,format="day.mon.year",
> > origin=c(month = 1, day = 1, year = 1960))
> > 
> > When I use describe on the dataframe I get this error:
> > 
> > Error in Ops.dates(weights, x) : * not defined for chron objects
> > 
> > Has anyone had this problem? I had used the same method with an older
> > version of R and HMisc and it worked. 
> > 
> > Should be be formatting date variables differently?
> > 
> > Thank you!
> > 
> > Sincerely,
> > Tanya Murphy
> > 
> 
> In recent versions, describe for R recognizes date/times by one of the
> following classes: 'POSIXt','POSIXct','chron'. If you really need to use
> another date format I could be talked into extending the code for that if
> you can remind me where dates( ) is found. -Frank
> 
> ---
> Frank E Harrell Jr Professor and Chair School of Medicine
> Department of Biostatistics Vanderbilt University
>