[R] boxplot in subgroups

[Pooja Jain]

Thank you very much Annette,

With your help I can do exactly what I wanted to.

Best wishes,
-Pooja
On 26 Mar 2009, at 06:59, Annette Heisswolf wrote:

> Hei,
>
> the error message below just tells you that you have specified nine  
> places along the axis where you want to have labels (i.e. at=1:9)  
> but obviously you have only specified three labels (i.e. labels =  
> c("C","M","S")). Thus, R is complaining that there are not enough  
> labels for all positions. However, I guess from your description  
> that you want to have only three labels below your plot, one for  
> each group of three boxes that share the same ASA1 value. Thus, you  
> could for example do like this:
>
> axis(side=1,at=c(2,5,8),labels=c("C","S","M"))
>
> Then you would get the label always below the middle one of the  
> three boxes of each group.
>
> Now the boxes are, however, still distributed evenly across the  
> plot, but in case you want to have those that belong to the same  
> subgroup a bit closer together, you can specify their position via  
> the "at" option on the boxplot function (see ?boxplot).
>
> An example with random data might look like this:
>
> ASA1=factor(rep(c("C","S","M"),each=100))
> ASA2=factor(rep(c("C","S","M"),100))
> C1_C2=runif(300)
> boxplot(C1_C2~ASA2*ASA1,xlim=c(0,12),at=c(1:3,5:7,9:11),xaxt="n")
> axis(side=1,at=c(2,6,10),labels=c("C","S","M"))
>
> See ?axis for further options, e.g. tcl=0 in case you don't want to  
> have a tick at the axis at the position of the label.
>
> Hope that helps,
>
> Annette
>
> Pooja Jain schrieb:
>> Hi,
>> I have data that looks like this:
>> ASA1    ASA2    C1_C2
>> C       M       9.0225
>> S       S       2.4315
>> M       C       3.4894
>> M       S       4.5282
>> C       M       1.3183
>> C       S       1.3735
>> S       C       1.0488
>> S       M       7.948
>> M       C       4.5827
>> I need to plot Boxplots for a given ASA1 (either C,S, or M) with  
>> respect to C1_C2. However, instead of one boxplot I want to plot  
>> three boxplots for a given ASA1 value such that each sub-boxplot  
>> represent the distribution for C1-C2 for each of the three possible  
>> values of ASA2 (C,S or M). I want to show this subgroup with a  
>> single xtics (either C, S or M) corresponding to the ASA1 value  
>> selected.
>> I tried to do it, but ending with the following error. I am not  
>> sure how exactly I should build the object to plot as subgroup.
>> Error in axis(side = 1, at = 1:9, labels = c("C", "M", "S" :
>>  'at' and 'labels' lengths differ, 9 != 3
>> In addition: Warning message:
>> In bxp(list(stats = c(1e-04, 2.82745, 6.0193, 10.5957, 22.2476,  :
>>  some notches went outside hinges ('box'): maybe set notch=FALSE
>> I would greatly appreciate any help in this matter.
>> Thank you.
>> -Kanu
>
> -- 
> Annette Heisswolf
> Section of Ecology
> Department of Biology
> University of Turku
> 20014 Turku, Finland
>
> phone	+ 358 2 333 6006
> fax	+ 358 2 333 6550
> mail	annette.heisswolf at utu.fi