R help - Nov 2007 - formatting POSIXlt object as strip labels in lattice plot

Dear list,

I'm plotting a lattice plot

xyplot(Volume ~ Weight | as.character(DateTime))

where DateTime is a POSIXlt object.  This produces strip labels in 
the format e.g. "2007-11-15 23:15:00" and panels are plotted in the 
correct order.  I'd prefer a format "15 Nov 23:15", but if I use 
format(DateTime,format="%d %b %H:%M") to do the conversion, then the 
panels are ordered according to the day of the month, ie the 
character string "15 Nov 23:15" etc.

How do I get labels in the required format, but panels in the correct order?

Thanks,
John

========================John Field Consulting Pty Ltd
10 High Street, Burnside SA 5066
Phone 08 8332 5294 or 0409 097 586
Fax   08 8332 1229
Email  JohnField at ozemail.com.au

Create a custom strip function which changes the names
of the factor levels.  Here we have changed them from 1:2
to c("b", "a").

my.strip <- function(..., factor.levels) {
   factor.levels <- c("b", "a")
   strip.default(..., factor.levels = factor.levels)
}

x <- 1:10
y <- x*x
z <- gl(2, 5)
xyplot(y ~ x | z, strip = my.strip)


On Nov 22, 2007 10:42 PM, John Field <JohnField at ozemail.com.au>
wrote:
> Dear list,
>
> I'm plotting a lattice plot
>
> xyplot(Volume ~ Weight | as.character(DateTime))
>
> where DateTime is a POSIXlt object.  This produces strip labels in
> the format e.g. "2007-11-15 23:15:00" and panels are plotted in
the
> correct order.  I'd prefer a format "15 Nov 23:15", but if I
use
> format(DateTime,format="%d %b %H:%M") to do the conversion, then
the
> panels are ordered according to the day of the month, ie the
> character string "15 Nov 23:15" etc.
>
> How do I get labels in the required format, but panels in the correct
order?
>
> Thanks,
> John
>
> ========================> John Field Consulting Pty Ltd
> 10 High Street, Burnside SA 5066
> Phone 08 8332 5294 or 0409 097 586
> Fax   08 8332 1229
> Email  JohnField at ozemail.com.au
>
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