Spidergraph in R - r

Question

The following is some code that produces various spider graphs:
# Data must be given as the data frame, where the first cases show maximum.
maxmin <- data.frame(
total=c(5, 1),
phys=c(15, 3),
psycho=c(3, 0),
social=c(5, 1),
env=c(5, 1))
# data for radarchart function version 1 series, minimum value must be omitted from above.
RNGkind("Mersenne-Twister")
set.seed(123)
dat <- data.frame(
total=runif(3, 1, 5),
phys=rnorm(3, 10, 2),
psycho=c(0.5, NA, 3),
social=runif(3, 1, 5),
env=c(5, 2.5, 4))
dat <- rbind(maxmin,dat)
op <- par(mar=c(1, 2, 2, 1),mfrow=c(2, 2))
radarchart(dat, axistype=1, seg=5, plty=1, vlabels=c("Total\nQOL", "Physical\naspects",
"Phychological\naspects", "Social\naspects", "Environmental\naspects"),
title="(axis=1, 5 segments, with specified vlabels)")
radarchart(dat, axistype=2, pcol=topo.colors(3), plty=1, pdensity=30, pfcol=topo.colors(3),
title="(topo.colors, fill, axis=2)")
radarchart(dat, axistype=3, pty=32, plty=1, axislabcol="grey", na.itp=FALSE,
title="(no points, axis=3, na.itp=FALSE)")
radarchart(dat, axistype=1, plwd=1:5, pcol=1, centerzero=TRUE,
seg=4, caxislabels=c("worst", "", "", "", "best"),
title="(use lty and lwd but b/w, axis=1,\n centerzero=TRUE, with centerlabels)")
par(op)
The output of the graphs consists of two sets of line segments with different colors. Where did the second set of line segments come from? Also what is a good way to graph multiple items on the same spider graph?

Answer 1

You should mention that you are using the fmsb library to create the graph. The code you show is the example in the documentation. The puzzling thing at first glance is why three sets of lines are shown (not two as you imply with "second set") while there are 5 records in dat.
It is all in that same documentation you took the code from:
row 1 = the maximum values (defined in `maxmin` in the example code)
row 2 = minimum values (defined in `maxmin` in the example code)
row 3 to 5 are example data points, each row leading to one of the
three line segments that you see in the example graphs.
Just read the documentation for radarchart {fmsb} again and play with the numbers in the example as you do so. It should be pretty clear what is happening and what options you have for your own data. You can add as many data-rows and create corresponding lines as you wish. But these do tend to become unreadable if you overdo it.