[R] converting character vector "hh:mm" to chron or strptime 24 clock time vectors

[Jim Lemon]

On 02/16/2010 09:47 PM, Alex Anderson wrote:
> ...
This is the problem
> 6 96.88 2008/04/24 24:00
>
> Error in `$<-.data.frame`(`*tmp*`, "time2", value = list(sec = c(0, 0, :
> replacement has 9 rows, data has 10

Hi Alex,
You have a problem with an invalid time. The line should read:

6 96.88 2008/05/24 00:00

However, there is something else going on here that puzzles me. When I 
tried this with your sample data:

tdata$datetime<-strptime(paste(tdata$date,tdata$time,sep="-"),"%Y/%m/%d-%H:%M")
Error in `$<-.data.frame`(`*tmp*`, "datetime", value = list(sec = c(0,  :
   replacement has 9 rows, data has 6

Yet:

datetime<-strptime(paste(tdata$date,tdata$time,sep="-"),
  "%Y/%m/%d-%H:%M")
datetime
[1] "2008-04-24 02:00:00" "2008-04-24 04:00:00" "2008-04-24 06:00:00"
[4] "2008-04-24 08:00:00" "2008-04-24 10:00:00" "2008-05-24 00:00:00"
length(datetime)
[1] 9

This is the first time I have encountered a discrepancy between "length" 
and the printed extent of an object, and I can't work out what is going on.

Jim