R help - Oct 2003 - strptime command in R

Hello all:

I have a column of times in format

   x
"16:30:00"
"16:30:03"
"16:59:00"
etc

which I need to convert into time variables and do some operations on.

I do the command y<-strptime(x,"%H:%M:%S"). This executes almost
istantly (for
a column x of length 1000 in Windows, but in Unix, where I run my production 
jobs, this takes over 4 minutes. I know that generally my Unix box is much 
more powerfull than my Win machine, and R runs generally faster on Unix, but 
this particular command is very very slow. Why is that? How can I speed that 
up without having to parse the strings by hand?

Thank you very much,
Vlad.

It would appear to mean that your `Unix' box's strptime is seriously 
broken, but you could profile R (the process, not R profiling) to find 
out.

You could try using package chron to convert the strings and then 
as.POSIXct, but that's inelegant at best.

On Tue, 28 Oct 2003, morozov wrote:
> Hello all:
> 
> I have a column of times in format
> 
>    x
> "16:30:00"
> "16:30:03"
> "16:59:00"
> etc
> 
> which I need to convert into time variables and do some operations on.
> 
> I do the command y<-strptime(x,"%H:%M:%S"). This executes
almost istantly (for
> a column x of length 1000 in Windows, but in Unix, where I run my
production
> jobs, this takes over 4 minutes. I know that generally my Unix box is much 
> more powerfull than my Win machine, and R runs generally faster on Unix,
but
> this particular command is very very slow. Why is that? How can I speed
that
> up without having to parse the strings by hand?
> 
> Thank you very much,
> Vlad.
> 
> ______________________________________________
> R-help at stat.math.ethz.ch mailing list
> https://www.stat.math.ethz.ch/mailman/listinfo/r-help
> 
> 
-- 
Brian D. Ripley,                  ripley at stats.ox.ac.uk
Professor of Applied Statistics,  http://www.stats.ox.ac.uk/~ripley/
University of Oxford,             Tel:  +44 1865 272861 (self)
1 South Parks Road,                     +44 1865 272866 (PA)
Oxford OX1 3TG, UK                Fax:  +44 1865 272595