[Rd] bug in plot.ts?

[Simone Giannerini]

Rui,

thanks for looking into this and adding some relevant info,
to me it looks more like a bug than lack of documentation, in any case
we'll see if anyone of the core team would like to comment.

Ciao

Simone

On Sat, Dec 29, 2012 at 8:22 PM, Rui Barradas <ruipbarradas at sapo.pt> wrote:
> Just to add, on documentation, to my previous post. The following
> illustrates my point.
>
> # This is the last instruction in the original post.
> plot.ts(x=1, y=1, type="n", xy.labels=FALSE) # does not show the plot
>
> plot.ts(x=1, y=1, xy.labels=FALSE) # does show the plot, does not label it,
> documented
> plot.ts(x=1, y=1, type="n") # does show the plot (labels it), not properly
> documented
> plot.ts(x=1:151, y=1:151, type="n") # does not show the plot, documented
>
> Rui Barradas
> Em 29-12-2012 19:07, Rui Barradas escreveu:
>>
>> Hello,
>>
>> You're right, it has to do with the argument xy.labels. The relevant
>> lines in the source are
>> (file src/library/stats/R/ts.R, function plot.ts)
>>
>>           [...]
>>           n <- length(xy $ x)          #-> default for xy.l(ines|abels)
>>           if(missing(xy.labels)) xy.labels <- (n <= 150)
>>           if(!is.logical(xy.labels)) {
>>               if(!is.character(xy.labels))
>>                   stop("'xy.labels' must be logical or character")
>>               do.lab <- TRUE
>>           } else do.lab <- xy.labels
>>           [...]
>>           ptype <-
>>           if(do.lab) "n" else if(missing(type)) "p" else type
>>           plot.default(xy, type = ptype,
>>           [...]
>>           if(do.lab)
>>               text(xy, labels =
>>                if(is.character(xy.labels)) xy.labels
>>                else if(all(tsp(x) == tsp(y))) formatC(time(x), width = 1)
>>                else seq_along(xy$x),
>>                col = col, cex = cex)
>>           if(xy.lines)
>>               lines(xy, col = col, lty = lty, lwd = lwd,
>>                 type = if(do.lab) "c" else "l")
>>           [...]
>>
>> Note that this is executed only if both 'x' and 'y' are passed to plot.ts.
>> The variable 'do.lab' will control the plot.default type and whether the
>> points are labeled using text() and the lines() type.
>> This variable is set according to xy.labels. This behavior is more or
>> less documented in plot.ts:
>>
>> |"xy.labels|||logical, indicating if |text
>> <http://127.0.0.1:29428/library/stats/help/text>()| labels should be
>> used for an x-y plot, /or/ character, supplying a vector of labels to be
>>
>> used. The default is to label for up to 150 points, and not for more."
>>
>> but I believe the documentation could be more clear. It could say that
>> in the case of a y ~ x plot, to supress the plot xy.labels should be set
>> to FALSE.
>>
>> Hope this helps,
>>
>> Rui Barradas
>> Em 29-12-2012 17:04, Simone Giannerini escreveu:
>>>
>>> Dear all,
>>>
>>> I think I have found a buglet in plot.ts
>>>
>>> plot.ts(x=1,type="n")     # correct: does not show the plot
>>> plot.ts(x=1,y=1,type="n") # not correct: does show the plot
>>>
>>> I did not investigate the problem in depth but it could be related to
>>> the switch xy.labels, in fact
>>>
>>> plot.ts(x=1,y=1,type="n",xy.labels=TRUE) #  does show the plot
>>> plot.ts(x=1,y=1,type="n",xy.labels=FALSE) # does not show the plot
>>>
>>>> sessionInfo()
>>>
>>> R version 2.15.2 Patched (2012-10-26 r61028)
>>> Platform: x86_64-w64-mingw32/x64 (64-bit)
>>>
>>> locale:
>>> [1] LC_COLLATE=Italian_Italy.1252  LC_CTYPE=Italian_Italy.1252
>>> [3] LC_MONETARY=Italian_Italy.1252 LC_NUMERIC=C
>>> [5] LC_TIME=Italian_Italy.1252
>>>
>>> attached base packages:
>>> [1] stats     graphics  grDevices utils     datasets  methods   base
>>>
>>> loaded via a namespace (and not attached):
>>> [1] tools_2.15.2
>>>
>>>
>>> Kind regards
>>>
>>> Simone
>>> ______________________________________________________
>>>
>>>
>>> Simone Giannerini
>>> Dipartimento di Scienze Statistiche "Paolo Fortunati"
>>> Universita' di Bologna
>>> Via delle belle arti 41 - 40126  Bologna,  ITALY
>>> Tel: +39 051 2098262  Fax: +39 051 232153
>>> http://www2.stat.unibo.it/giannerini/
>>>
>>> ______________________________________________
>>> R-devel at r-project.org mailing list
>>> https://stat.ethz.ch/mailman/listinfo/r-devel
>>
>>
>>         [[alternative HTML version deleted]]
>>
>>
>> ______________________________________________
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>
>



-- 
___________________________________________________

Simone Giannerini
Dipartimento di Scienze Statistiche "Paolo Fortunati"
Universita' di Bologna
Via delle belle arti 41 - 40126  Bologna,  ITALY
Tel: +39 051 2098262  Fax: +39 051 232153
http://www2.stat.unibo.it/giannerini/