How to align labels with coord_polar?

Question

I am trying to produce a circular "heatmap" in R, and found a solution with coord_polar, and how to distribute the labels around the plot.

My problem is that the labels around the plot seem to be centred and the long names are overlapping the plot. I can't use hjust and vjust to align the text to the edge of the plot.

My code and a subset of my data:

library(reshape)
library(ggplot2)

data <- data.frame(id=c("S_subsp_houtenae_str_ATCC_BAA-1581","S_Heidelberg_S_1_7","S_Haifa_S_11_3","S_Infantis_S_2_3","S_Newport_S_1_4","S_Bredeney_S_1_3","S_Saint_Paul_S_1_5","S_Bovismorbificans_S_3_8","S_Saintpaul_str_SARA26","S_London_S_6_7","S_Mbandaka_S_7_5","S_Corvallis_S_5_6","S_San_Diego_S_9_5","S_Javiana_str_10721"),
            A.C2=c(0,0,0,0,0,0,0,0,0,0,0,2,0,0),Col156=c(0,0,0,0,0,4,0,0,0,0,0,0,0,0),
            ColRNAI=c(0,8,0,0,8,8,8,0,8,0,0,0,0,0),FIB=c(0,0,0,0,10,0,0,10,10,0,0,0,0,0),
            FII=c(0,0,0,0,0,0,0,12,12,0,0,0,0,0),HI2=c(0,15,0,0,15,15,0,0,0,0,0,0,0,0),
            HI2A=c(0,15,0,0,15,15,0,0,0,0,0,0,0,0),I1=c(0,17,17,17,0,0,0,0,0,0,0,17,17,0),
            I2=c(0,0,0,0,0,0,0,0,0,0,0,18,18,18),N=c(0,0,0,0,0,0,0,19,19,19,19,0,0,0),
            P=c(20,20,20,20,20,20,20,0,0,0,0,0,0,0),Q1=c(0,22,0,0,22,0,0,0,0,0,0,22,0,0))
data <- transform(data,id=factor(id,levels=unique(id)))

data.m <- melt(data) 
data.m$var2 = as.numeric(data.m$variable) + 15
y_labels = levels(data.m$variable)
y_breaks = seq_along(y_labels) + 15

sequence_length = length(unique(data.m$id))
first_sequence = c(1:(sequence_length%/%2)) 
second_sequence = c((sequence_length%/%2+1):sequence_length) 
first_angles =c(90 - 180/length(first_sequence) * first_sequence)
second_angles = c(-90 - 180/length(second_sequence) * second_sequence)

Palette <- c("#f1f1f1","#302013","#614126","#58DB41","#638A5C","#62D585","#579134","#B8DD95","#9ED84D","#4B6FC8","#2A344D","#47689B","#315CEE","#D9AB68","#E09B33","#FE9E2A","#D97B0C","#6A2F45","#A02A77","#E1C73E","#D16F60","#C13420","#DA435C","#E20338","#000000","#999999")

p = ggplot(data.m, aes(x=id, y=var2, fill=factor(value))) + 
geom_tile(colour="white") + 
scale_fill_manual(values=Palette) +
scale_y_discrete(breaks=y_breaks, labels=y_labels) + 
theme(panel.background=element_blank(),
axis.title=element_blank(),
panel.grid=element_blank(),
axis.text.x=element_text(angle= c(first_angles,second_angles),size=8),
axis.ticks=element_blank(),
axis.text.y=element_blank(),
legend.position="none")

p = p + coord_polar()
plot(p) 

Answer 1

I've had similar issues in coord_polar() with labels not responding to either hjust= or vjust= and therefore not aligning as I'd like.

The solution to this, shown here https://stackoverflow.com/a/28846989/4340137, is to use geom_text() to manually label the data.

The example at the link provided does everything you need. Unfortunately, I just can't get it working quickly with your more complicated data structure and SO won't let me leave this as a comment.

Someone else may be able to edit to include the exact code.

Answer 2

In RStudio, when I run the following and zoom, all the labels are outside the circle except the longest one, which may mean the plot margin at the top is too tight (or you might consider shortening the name or using \n for a new line). I changed the axis.text.y argument to theme. I also couldn't get the odd legend in the top left to go away. Even so, the inserted plot suffers from the overlap problem you described.

ggplot(data.m, aes(x=id, y=var2, fill=factor(value))) + 
  geom_tile(colour="white") + 
  scale_fill_manual(values=Palette) +
  scale_y_discrete(breaks=y_breaks, labels=y_labels) + 
  theme(panel.background=element_blank(), axis.title=element_blank(), panel.grid=element_blank(),
        axis.text.x=element_text(angle= c(first_angles,second_angles),size=8, vjust=-1), # vjust=-1
        axis.ticks=element_blank(), legend.position="none", 
        axis.text.y=element_text(vjust = -2), legend.position="none") +
  coord_polar()