[R] Unintended behaviour (possibly bugs)

Alexey Shipunov d@cty|orh|z@ @end|ng |rom gm@||@com
Tue Feb 18 06:34:48 CET 2020


Thank you for the detailed explanation. I tend to agree. However, this
behavior is relatively easy to remediate:

This is the piece of the current code:

===
   if (!(is.null(labels) && is.null(glabels))) {
        nmai <- par("mai")
        nmai[2L] <- nmai[4L] + max(linch + goffset, ginch) + 0.1
        par(mai = nmai)
    }
===

This is my proposal:

===
    yinch <- if (!is.null(ylab)) 0.4 else 0
    if (!(is.null(labels) && is.null(glabels))) {
        nmai <- par("mai")
        nmai.2.new <- nmai[4L] + max(yinch + linch + goffset,
            ginch) + 0.1
        if (nmai.2.new > nmai[2L]) {
            nmai[2L] <- nmai.2.new
        }
        par(mai = nmai)
    }
===

Then margins and y-axis labels start to work normally. I wonder if
this (or similar) is possible to introduce into the code?

Alexey

пн, 17 февр. 2020 г. в 17:37, Deepayan Sarkar <deepayan.sarkar using gmail.com>:
>
> On Mon, Feb 17, 2020 at 10:24 AM Rui Barradas <ruipbarradas using sapo.pt> wrote:
> >
> > Hello,
> >
> > Yes, this is definitely a bug.
>
> I would argue that the only bug here is that the documentation doesn't
> say that 'ylab' may not behave as expected.
>
> dotchart() is mainly designed for 2-way tables (see the VADeaths
> example), but it's implementation is really pretty hackish because it
> has to work within the limited traditional graphics framework. The
> main problem is that dot plots want to put horizontal y-axis labels
> (usually derived from factor levels), which are often longer than the
> default margins, so the margins are modified. Unfortunately they are
> only re-set on exit, and so the ylab that is plotted inside dotchart()
> may be clipped. Traditionally, Cleveland dot plots don't have a y-axis
> label; it's assumed that the factor levels are sufficient (and for
> 2-way tables, there would be two variables, so there is no sensible
> default).
>
> I doubt that dotchart() is worth fixing (except to maybe disallow
> ylab). If you want flexibility, use modern grid-based alternatives
> such as lattice::dotplot() or ggplot2.
>
> -Deepayan
>
> > Even the matrix plot is puzzling, with a "1" as top row sort-of-label
> > but no grid line. I'm trying to follow the source code of dotchart but
> > am yet to understand exactly what it does to decide the margins settings.
> >
> >      if (!(is.null(labels) && is.null(glabels))) {
> >        nmai <- par("mai")
> >        nmai[2L] <- nmai[4L] + max(linch + goffset, ginch) +
> >          0.1
> >        par(mai = nmai)
> >      }
> >
> > This should be moved to r-devel?
> >
> > Rui Barradas
> >
> > Às 03:33 de 17/02/20, Alexey Shipunov escreveu:
> > > John and Rui, thanks!
> > >
> > > However, if we use the proper object, the problem still persists:
> > >
> > > dotchart(c("3"=1, "2"=2, "1"=3), ylab="Ylab") # ylab is invisible
> > > dotchart(c("aa"=1, "b"=2, "cc"=3), ylab="Ylab") # ylab is partly visible (!!!)
> > > dotchart(c("aaa"=1, "bbb"=2, "ccc"=3), ylab="Ylab") # ylab is well visible
> > >
> > > If the object is matrix, ylab is visible:
> > >
> > > dotchart(matrix(1:3, dimnames=list(c("aa","bb","cc"), NULL)), ylab="Ylab")
> > >
> > > But the ?dotchart explicitly says that "x: either a vector or matrix
> > > of numeric values" and then "labels: a vector of labels for each
> > > point.  For vectors the default is to use ‘names(x)’ ...".
> > >
> > > So this is likely a bug. Do you agree?
> > >
> > > Alexey
> > >
> > > пн, 17 февр. 2020 г. в 01:55, Rui Barradas <ruipbarradas using sapo.pt>:
> > >>
> > >> Hello,
> > >>
> > >> I believe you are wrong, the error is not in dotchart, it's in your
> > >> code. You assume that to plot an object of class "table" is the same as
> > >> to plot an object of class "numeric".
> > >>
> > >> Inline.
> > >>
> > >> Às 12:21 de 16/02/20, Alexey Shipunov escreveu:
> > >>> Dear list,
> > >>>
> > >>> I have been advised to share these with R-help instead of filling the
> > >>> bug report:
> > >>>
> > >>> 1) dotchart() does not allow to see the left axis title ('ylab') and
> > >>> cannot change the left margin (outer margin 2) of the plot
> > >>>
> > >>> The code:
> > >>>
> > >>> aa <- table(c(1, 1, 1, 2, 2, 3))
> > >>> dotchart(aa, ylab="Ylab") # does not show 'ylab'
> > >>
> > >> You are right, it does *not* show 'ylab' but the user is warned.
> > >>
> > >>
> > >> aa <- table(c(1, 1, 1, 2, 2, 3))
> > >> dotchart(aa, ylab = "Ylab") # does show 'ylab'
> > >> #Warning message:
> > >> #In dotchart(aa, ylab = "Ylab") :
> > >> #  'x' is neither a vector nor a matrix: using as.numeric(x)
> > >>
> > >>
> > >> My code:
> > >>
> > >>
> > >> (mar <- par("mar"))    # new R session
> > >> #[1] 5.1 4.1 4.1 2.1   # the left margin is 4.1
> > >>
> > >> aa <- as.numeric(table(c(1, 1, 1, 2, 2, 3)))
> > >>
> > >> dotchart(aa, ylab = "Ylab") # It does show 'ylab'
> > >> old.par <- par(mar = mar + c(0, 5, 0, 0))
> > >> par("mar")
> > >> #[1] 5.1 9.1 4.1 2.1
> > >>
> > >> dotchart(aa, ylab = "Ylab")  # The left margin is now 9.1, much bigger
> > >>
> > >> par(old.par)                 # It does change the left margin
> > >> dotchart(aa, ylab = "Ylab")  #  but only when a new graph is plotted.
> > >>
> > >>
> > >>
> > >>> old.par <- par(mar=c(1, 10, 1, 1)) ; dotchart(aa, ylab="Ylab") ;
> > >>> par(old.par) # does not change left margin
> > >>>
> > >>> Possible solution:
> > >>>
> > >>> I researched the problem and think that the dotchart() code will need
> > >>> few corrections. If there is an interest, I can post it here; or you
> > >>> can look at the code of shipunov::Dotchart1() function.
> > >>>
> > >>> 2) example(hist) includes two "wrong" and "extreme" examples which
> > >>> slow down and even crash R on some systems; this make it unsuitable
> > >>> for demonstration in the class and strikes beginners in R who just
> > >>> want to understand how hist() works. Actually, I did it last week (I
> > >>> was not aware of these examples), and in the class two computers hang,
> > >>> and many others were extremely slow.
> > >>>
> > >>> The code:
> > >>>
> > >>> example(hist)
> > >>>
> > >>> Possible solution:
> > >>>
> > >>> If R maintainers will enclose parts of "hist" example in \dontrun{},
> > >>> this will allow to see the code but in the same time will not strike
> > >>> beginners in R who just
> > >>> want to understand how hist() works. They will still be possible to
> > >>> run with example(..., run.dontrun=TRUE).
> > >>
> > >> Agree, it's annoying. Sometimes there's a Warning section after the
> > >> Details section. Maybe such a section could get users' attention to
> > >> those examples? At least it wouldn't hurt...
> > >>
> > >>
> > >> Hope this helps,
> > >>
> > >> Rui Barradas
> > >>
> > >>>
> > >>> With best wishes,
> > >>>
> > >>> Alexey Shipunov
> > >>>
> > >>> ______________________________________________
> > >>> R-help using r-project.org mailing list -- To UNSUBSCRIBE and more, see
> > >>> https://stat.ethz.ch/mailman/listinfo/r-help
> > >>> PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
> > >>> and provide commented, minimal, self-contained, reproducible code.
> > >>>
> > >
> > > ______________________________________________
> > > R-help using r-project.org mailing list -- To UNSUBSCRIBE and more, see
> > > https://stat.ethz.ch/mailman/listinfo/r-help
> > > PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
> > > and provide commented, minimal, self-contained, reproducible code.
> > >
> >
> > ______________________________________________
> > R-help using r-project.org mailing list -- To UNSUBSCRIBE and more, see
> > https://stat.ethz.ch/mailman/listinfo/r-help
> > PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
> > and provide commented, minimal, self-contained, reproducible code.



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