[R] Boxplot with Log10 and base-exponent axis

William Dunlap wdunlap at tibco.com
Fri Jun 22 17:31:29 CEST 2012


You might prefer placing the tick marks with
  log10AtY <- log10(axTicks(side=2))
  log10AtY <- unique(round(log10AtY))
instead of the
  ylim <- par("usr")[3:4]
  log10AtY <- seq(ceiling(ylim[1]), floor(ylim[2]))
in my original example.

Bill Dunlap
Spotfire, TIBCO Software
wdunlap tibco.com


> -----Original Message-----
> From: r-help-bounces at r-project.org [mailto:r-help-bounces at r-project.org] On Behalf
> Of William Dunlap
> Sent: Friday, June 22, 2012 8:14 AM
> To: Luigi; r-help at r-project.org
> Subject: Re: [R] Boxplot with Log10 and base-exponent axis
> 
> The key is to supply an expression, not text, to the labels argument to axis.
> See help("plotmath") for details.  Here is an example:
>   x <- list(One=10^(sin(1:10)+5), Two=10^(cos(1:30)*2))
>   boxplot(x, log="y", yaxt="n")
>   ylim <- par("usr")[3:4]
>   log10AtY <- seq(ceiling(ylim[1]), floor(ylim[2]))
>   axis(side=2, at=10^log10AtY, lab=as.expression(lapply(log10AtY,
> function(y)bquote(10^.(y)))))
> 
> Bill Dunlap
> Spotfire, TIBCO Software
> wdunlap tibco.com
> 
> > -----Original Message-----
> > From: r-help-bounces at r-project.org [mailto:r-help-bounces at r-project.org] On Behalf
> > Of Luigi
> > Sent: Friday, June 22, 2012 7:54 AM
> > To: r-help at r-project.org
> > Subject: [R] Boxplot with Log10 and base-exponent axis
> >
> > Dear all,
> >
> > I would like to (i) produce boxplot graphs with axis in logarithm in base 10
> > and (ii) showing the values on the axis in 10^exponent format rather than
> > 10E+exponent.
> >
> >
> >
> > To illustrate with an example, I have some widely spread data that I chart
> > plot using  boxplot() [figure on the left]; the log="y" option of boxplot()
> > I obtained the natural logarithm conversion of the data and the unfriendly
> > notation baseE+exponent [figure on the centre]; if I log10 the data I obtain
> > the desired plot, but the axis are showing only the exponent. [figure on the
> > right].
> >
> >
> >
> > Can anybody help?
> >
> >
> >
> > Best regards
> >
> > Luigi Marongiu, MSc
> >
> >
> >
> > ########### EXAMPLE ############
> >
> > # generationg random numbers
> >
> > x<-runif(100, min=0, max=100000)
> >
> >
> >
> > # create plot
> >
> > par(mfrow = c(1,3))
> >
> >
> >
> > #plotting in the left side
> >
> > boxplot(x, xlab="Linear values")
> >
> >
> >
> > #plotting in the centre
> >
> > boxplot(x, log = "y", xlab="y axis logged")
> >
> >
> >
> > # creating log10 values and plotting on the right side
> >
> > Log.base10.x<-log10(x)
> >
> > boxplot(Log.base10.x, xlab="LOG10 of data")
> >
> >
> >
> >
> >
> >
> > 	[[alternative HTML version deleted]]
> >
> > ______________________________________________
> > R-help at r-project.org mailing list
> > 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 at r-project.org mailing list
> 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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