R help - Jun 2010 - ggplot2 boxplot: horizontal, univariate

In ggplot2, I would like to make a boxplot that has the following properties:

(1) Contrary to default, the meaningful axis should be the horizontal axis.

Lattice does this, for instance, by

library(lattice);bwplot(~mtcars$mpg)

(2) It is *univariate*, i.e., of a single vector, say mtcars$mpg.  I do not wish
to make separate plots for the different values of mtcars$cyl.

(3) Nothing on the meaningless axis--the axis that does not correspond to values
of mtcars$mpg, the axis which by default is horizontal--should suggest a scale.
Thus, there should be no axis title or label; there should be no axis ticks.

Partial solutions:

To achieve (1), one might save a vertical plot (with mpg on the y-axis) as a pdf
and use Adobe Acrobat to rotate it 90 degrees. But is there not a way to do this
*within* ggplot2?

Since ggplot2 has been carefully thought out starting with the grammar of
graphics, I wonder if there is some conceptual argument against making
univariate boxplots and against boxplots with a horizontal continuous axis.

But in teaching an introductory statistics course, I would like to compare the
ways that a histogram and a boxplot summarize a single continuous variable. Thus
I would like the continuous axis to be horizontal in both plots.

The following code achieves (2) and part of (3):

library(ggplot2)

qplot(factor(0), mpg, data=mtcars, geom="boxplot", xlab="")+
opts(axis.text.x = theme_blank(), axis.ticks=theme_blank())

but to remove the ticks from the meaningless (horizontal) axis I had to also
remove the ticks from the meaningful (vertical) axis.  On page 143 of
Wickham's ggplot2 book, I find axis.ticks as a theme element but nothing
like axis.ticks.x.

Is there a way to remove the axis ticks from the x axis and not from the y axis?

But, more important: How do I make a boxplot that is rotated (or transposed)
from the default, so that the x axis carries the information?

Thanks

Jacob A. Wegelin
Assistant Professor
Department of Biostatistics
Virginia Commonwealth University
730 East Broad Street Room 3006
P. O. Box 980032
Richmond VA 23298-0032
U.S.A.

Try this,

qplot(factor(0), mpg, data=mtcars, geom="boxplot", xlab="")+
coord_flip() + scale_x_discrete(breaks=NA)

HTH,

baptiste
On 18 June 2010 16:47, Jacob Wegelin <jacobwegelin at fastmail.fm>
wrote:
>
> In ggplot2, I would like to make a boxplot that has the following
> properties:
>
> (1) Contrary to default, the meaningful axis should be the horizontal axis.
>
> Lattice does this, for instance, by
>
> library(lattice);bwplot(~mtcars$mpg)
>
> (2) It is *univariate*, i.e., of a single vector, say mtcars$mpg. ?I do not
> wish to make separate plots for the different values of mtcars$cyl.
>
> (3) Nothing on the meaningless axis--the axis that does not correspond to
> values of mtcars$mpg, the axis which by default is horizontal--should
> suggest a scale. Thus, there should be no axis title or label; there should
> be no axis ticks.
>
> Partial solutions:
>
> To achieve (1), one might save a vertical plot (with mpg on the y-axis) as
a
> pdf and use Adobe Acrobat to rotate it 90 degrees. But is there not a way
to
> do this *within* ggplot2?
>
> Since ggplot2 has been carefully thought out starting with the grammar of
> graphics, I wonder if there is some conceptual argument against making
> univariate boxplots and against boxplots with a horizontal continuous axis.
>
> But in teaching an introductory statistics course, I would like to compare
> the ways that a histogram and a boxplot summarize a single continuous
> variable. Thus I would like the continuous axis to be horizontal in both
> plots.
>
> The following code achieves (2) and part of (3):
>
> library(ggplot2)
>
> qplot(factor(0), mpg, data=mtcars, geom="boxplot",
xlab="")+
> opts(axis.text.x = theme_blank(), axis.ticks=theme_blank())
>
> but to remove the ticks from the meaningless (horizontal) axis I had to
also
> remove the ticks from the meaningful (vertical) axis. ?On page 143 of
> Wickham's ggplot2 book, I find axis.ticks as a theme element but
nothing
> like axis.ticks.x.
>
> Is there a way to remove the axis ticks from the x axis and not from the y
> axis?
>
> But, more important: How do I make a boxplot that is rotated (or
transposed)
> from the default, so that the x axis carries the information?
>
> Thanks
>
> Jacob A. Wegelin
> Assistant Professor
> Department of Biostatistics
> Virginia Commonwealth University
> 730 East Broad Street Room 3006
> P. O. Box 980032
> Richmond VA 23298-0032
> U.S.A.
>
> ______________________________________________
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> 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.
>