Spider plots in R

This is mainly a note for myself

Lets create some data

dat = data.frame(E1=rnorm(10,2.5), E2=rnorm(10,1.5), E3=rnorm(10,3))

dat$Activity=c(1,1,1,2,2,2,3,3,3,3)

I want to draw spider plot using a mean values of each column grouped by Activity

require(plyr)

cdata <- ddply(dat, c("Activity"), summarise, E1 = mean(E1), E2=mean(E2), E3=mean(E3)

radar char requires Max, Min and data to be drawn. Above we transformed data so that we have mean values for E1, E2, and E3 in one row per condition. Next, we add a row that contains minimum values for radarchart command:

cdata=rbind(c(0,0,0), cdata)

Next, we add row containing maximum values for radarchart

cdata=rbind(c(5,5,5), cdata)

We need names Max, Min so that radarchar finds those (it might be that the order would be enough but I did not test).

rownames(cdata) = c("Max", "Min", "A", "B", "C")

Finally, the spider chart.

require(fmsb)

radarchart(cdata[c("E1", "E2", "E3")])

---

cdata looks like

    Activity       E1       E2       E3
Max        5 5.000000 5.000000 5.000000
Min        0 0.000000 0.000000 0.000000
A          1 2.057835 1.735599 3.304232
B          2 2.226611 1.471724 3.370966
C          3 3.206408 1.572105 2.398983

And spider plot