On 10/12/2006 9:08 AM, Armstrong, Whit wrote:
> I've never had any issues with the way that plot.POSIXct chooses the
> labels of the date axis before, but in this particular case it's output
> is a little confusing.

It was wrong, but this was fixed in R-patched last week.  I've added an 
item to NEWS about it.

Duncan Murdoch

> 
> plot(seq(as.POSIXct("1997-10-01"),length.out=108,by="month"),rnorm(108))
> 
> This command produces a chart with every x tick mark labeled as "Jan
> 01".
> 
> I can replicate this chart by adding the format string "%b %d".
> 
> plot(seq(as.POSIXct("1997-10-01"),length.out=108,by="month"),rnorm(108),
> format="%b-%d")
> 
> My contention is that plot.POSIXct should choose "%Y" in this case,
> which would show unique labels rather than repeated labels.
> 
> plot(seq(as.POSIXct("1997-10-01"),length.out=108,by="month"),rnorm(108),
> format="%Y")
> 
> 
> 
> Now, just looking at axis.POSIXct it seems that the terminal condition
> of this if/else sequence sets format to "%b %d":
> 
>  }
>     else if (d < 7 * 60 * 60 * 24) {
>         sc <- 60 * 60 * 24
>         if (missing(format)) 
>             format <- "%a"
>     }
>     else {
>         sc <- 60 * 60 * 24
>         if (missing(format)) 
>             format <- "%b %d"  #****** here
>     }
> 
> 
> when the second set of if conditions fires up, format has already bet
> set, so the missing(format) test fails here and does not set the format
> to %Y:
> 
>  else {
>         class(z) <- c("POSIXt", "POSIXct")
>         zz <- as.POSIXlt(z)
>         zz$mday <- 1
>         zz$isdst <- zz$mon <- zz$hour <- zz$min <- zz$sec <- 0
>         zz$year <- pretty(zz$year)
>         z <- as.POSIXct(zz)
>         if (missing(format)) 
>             format <- "%Y"   #******  here
>     }
> 
> I'm not sure if this is the intended behavior or not.  Does anyone else
> have any thoughts on this issue?
> 
> Thanks,
> Whit
> 
> 
> 
> 
> 
> This e-mail message is intended only for the named recipient(s) above. It may 
> contain confidential information. If you are not the intended recipient you 
> are hereby notified that any dissemination, distribution or copying of this 
> e-mail and any attachment(s) is strictly prohibited. If you have received 
> this e-mail in error, please immediately notify the sender by replying to 
> this e-mail and delete the message and any attachment(s) from your system. 
> Thank you.
> 
> 
>       [[alternative HTML version deleted]]
> 
> ______________________________________________
> [email protected] mailing list
> https://stat.ethz.ch/mailman/listinfo/r-devel

______________________________________________
[email protected] mailing list
https://stat.ethz.ch/mailman/listinfo/r-devel

Reply via email to