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Boxplot Help for Neophyte

4 messages · Alex Park, Nolwenn LeMeur, Marc Schwartz (via MN) +1 more

Alex Park
# 
R helpers

I am getting to grips with R but came across a small problem today that I 
could not fix by myself.

I have 3 text files, each with a single column of data. I read them in 
using:

myData1<-scan("C:/Program Files/R/myData1.txt")
myData2<-scan("C:/Program Files/R/myData2.txt")
myData3<-scan("C:/Program Files/R/myData3.txt")

I wanted to produce a chart with 3 boxplots of the data and used:

boxplot(myData1, myData2, myData3)

This worked fine so I consulted R [help(bxp)] to add some format and labels 
e.g. title= , xlab =, ylab= , notch=TRUE etc. I managed to figure that ok.

However, I could not figure out how to get the labels myData1, myData2, and 
myData3 on the boxplot x-axis to denote which box was which (though I knew 
by looking). Can anybody help with this?

I trawled through my downloaded R pdfs but could not find a way.

Regards


Alex Park
Nolwenn LeMeur
# 
Hi Alex,
how about,

myData<-data.frame("myData1"=myData1,"myData2"=myData2,"myData3"=myData3)
boxplot(myData)

Nolwenn

**************************************
Nolwenn Le Meur, PhD
Fred Hutchinson Cancer Research Center
Computational Biology
1100 Fairview Ave. N., M2-B876
P.O. Box 19024
Seattle, WA 98109-1024
On Mon, 20 Feb 2006, Alex Park wrote:

            

      
      
      
    

        

      
      
    

  
  


  


      

    

    

      
      

        


  

        

      Marc Schwartz (via MN)
    

    

      
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On Mon, 2006-02-20 at 20:27 +0000, Alex Park wrote:

            

      
      
      
    

        
Alex,

You can use the 'names' argument to boxplot():

  boxplot(myData1, myData2, myData3, 
          names = c("myData1", "myData2", "myData"))

If you want additional flexibility, note that by default (unless you
change the 'at' argument), the group plots are drawn at integer axis
values of 1:n, where 'n' is the number of groups. See the 'at' argument
in ?boxplot.  You can then use mtext() to draw further text if desired.

HTH,

Marc Schwartz