I am trying to create nice (!) polar plot with the following data.
gr1 <- c(0, 5, 15, 20, 30, 40) gr3 <- c(0, 5, 10, 25, 40, 60, 80) gr2 <- c(0, 15, 25, 30, 40) df2<- data.frame (pos = c(gr1, gr2, gr3), group = c(rep(1, length(gr1)), rep(2, length(gr1)), rep(2, length(gr1)))) inner circle segment to mark first tier, group 1, between 15, 20 group 3, between 5, 10 between 40 to 60 second tier, group 1, between 15, 20 group 3, between 5, 10 between 10, 25 between 40 to 60
The angle between two lines between the interval between two pos.
there are more than two tier in my real data to plot.
The markers might be either segments or other marks such as filled colors.
Different group can color coded if possible.

Alternative with circle segment markings (preferred)

I tried it with ggplot2.
cx <- ggplot(df2, aes(x = pos, group = group) + geom_bar(width = 1, colour = "black")) Error in aes(x = pos, group = group) + geom_bar(width = 1, colour = "black") : non-numeric argument to binary operator cx + coord_polar()
More trials:
df2$cpos <- cumsum (df2$pos) cx <- ggplot(df2, aes(x = cpos, group = group) + geom_bar(width = 1, colour = "black"))
Edits 1:
I think I might be terrible to explain the issue. Here is figure with explanation.

The pos (position) is a continuous scale, angle in polar should depend upon where value of position is. It will restart once one group is done. I did a trick to cumsum to this trick (I might be wrong).
Edits 2:
The following answer opened more thoughts into the question. This is improved version but color management is not working.
df2$cpos <- cumsum (df2$pos) df2$y <- rep(3, length (df2$cpos)) cx <- ggplot(df2, aes(y = y, x = cpos)) cx + geom_bar(aes(stat = "identity",fill="yellow", colour = "yellow" )) + geom_point(aes(color = factor(group)), pch = 18, size = 2) + coord_polar() + scale_fill_manual(values=c("#CC6666", "#9999CC", "#66CC99"))+ ylim(0,3)

When I try to set ylim (2,3) so that they look like segments that do not work as well.
Error in data$y[data$y == -Inf] <- range$y.range[1] : replacement has length zero