R help - Sep 2011 - Specifying Start/End Dates for X-axis Range in plot()/xyplot()

I'm having difficulty finding the syntax to use to specify the beginning
and ending dates for the x-axis while plotting a zoo object. I thought that
I had seen a message on this list that used start=as.Date("...")
end=as.Date("..."), but I cannot find that message. I've tried
?plot,
?plotxy, ?plot.zoo, and Sarkar's lattice book.

   I am trying to plot the time series for 'Burns Mg' generated by:
> sapply(names(z), function(nm) range(time(na.omit(z[, nm]))), simplify =
FALSE)
$`Burns Mg`[1] "1994-01-20" "2009-11-11"

   This is a typical result of my trial-and-error approach:
> plot(z[, $'Burns Mg'], range(time(start =
as.Date("1994-01-20"), end = as.Date("2009-11-11"))))
Error in is.matrix(x) : 'x' is missing

   Please point me to documentation on specifying

TIA,

Rich

On Sep 20, 2011, at 7:15 PM, Rich Shepard wrote:
>  I'm having difficulty finding the syntax to use to specify the  
> beginning
> and ending dates for the x-axis while plotting a zoo object. I  
> thought that
> I had seen a message on this list that used start=as.Date("...")
> end=as.Date("..."), but I cannot find that message. I've
tried ?plot,
> ?plotxy, ?plot.zoo, and Sarkar's lattice book.
>
>  I am trying to plot the time series for 'Burns Mg' generated by:
>
>> sapply(names(z), function(nm) range(time(na.omit(z[, nm]))),  
>> simplify = FALSE)
> $`Burns Mg`[1] "1994-01-20" "2009-11-11"
>
>  This is a typical result of my trial-and-error approach:
>
>> plot(z[, $'Burns Mg'], range(time(start =
as.Date("1994-01-20"),
>> end = as.Date("2009-11-11"))))
> Error in is.matrix(x) : 'x' is missing
>   Please point me to documentation on specifying
It seems likely even if you got past that error, you would encounter  
problems from the hashed up syntax in this portion of that plot call:

z[, $'Burns Mg']

For better guessing,  supply the output of:

  dput(z)   # We have no idea what 'Burns Mg' has in it.

Or just use an example from the zoo pages.

Also: wrapping range() around a vector formed from two elements seems  
at the very best unnecessary and at the worst positively fraught with  
downside potential. And the 'time' function does not have arguments  
names start and stop.


-- 
David
>
> TIA,
>
> Rich
>
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David Winsemius, MD
West Hartford, CT