On Sep 16, 2012, at 07:48 , David Winsemius wrote:
>
> On Sep 15, 2012, at 7:15 PM, mcg wrote:
>
>> Hello R-users,
>>
>> I would like to use subscript in chemical formulas for the different
>> treatments in a boxplot.
>> Fot title, xlab and ylab sub- and superscript is no problem, but for the
>> different treatments of the following example I cannot get subscript.
>>
>> Example:
>> weight <- c(6,5,7,2,7,3,9,4,2,7,8,9,2,3,4,5)
>> treatments <- as.factor(rep(c('Control', 'P2O5','K2SO4','CaSO4'),4))
>> data <- data.frame(treatments,weight)
>> boxplot(data$weight~data$treatments)
>>
>> If I apply expression(P[2]...) I get "unimplemented type 'expression' in
>> 'HashTableSetup' ".
>> If there is a solution for this in base graphics or ggplot please let me
>> know.
>>
>
> ?plotmath
> boxplot(data$weight~data$treatments, xaxt="n")
> axis(1, 1:4, labels=expression(Control, P[2]*O[5], K[2]*SO[4], CaSO[4]) )
>
> I will admit that the need for the "*"'s was not apparent to me until I used
> the initial example as a starting point and made incremental changes until I
> gotsuccess. So I am not suggesting that RTM should have been enough.
Just remember that plotmath is designed to handle math expressions like
alpha+beta*x and the logic should follow. For the same reason, although it
makes little or no visual difference, you really should say
labels=expression(Control, P[2]*O[5], K[2]*S*O[4], Ca*S*O[4])
(Plotmath as of now doesn't actually do anything about kerning and such, but
TeX afficionados will know that $different$ is quite different from
\textit{different}, the former not being a word but identical to $dif^2e^2rnt$)
--
Peter Dalgaard, Professor,
Center for Statistics, Copenhagen Business School
Solbjerg Plads 3, 2000 Frederiksberg, Denmark
Phone: (+45)38153501
Email: pd....@cbs.dk Priv: pda...@gmail.com
______________________________________________
R-help@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.
