Boxplot Help for Neophyte
On Mon, 2006-02-20 at 20:27 +0000, Alex Park wrote:
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
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