Circular Heatmap that looks like a donut

Question

I\'m trying to create circular heatmap with ggplot2 so I can use a larger number of labels around the circumference of a circle. I\'d like to have it look more like a donut

Answer 1

Addressing @FedericoGiorgi's comment, not the original question. Thanks @bdemarest your solution is incredibly useful!

Hack together a data frame to display labels, arrange them nicely:

nba.labs <- subset(nba.m, variable==levels(nba.m$variable)[nlevels(nba.m$variable)])
nba.labs <- nba.labs[order(nba.labs$Name),]
nba.labs$ang <- seq(from=(360/nrow(nba.labs))/1.5, to=(1.5*(360/nrow(nba.labs)))-360, length.out=nrow(nba.labs))+80
nba.labs$hjust <- 0
nba.labs$hjust[which(nba.labs$ang < -90)] <- 1
nba.labs$ang[which(nba.labs$ang < -90)] <- (180+nba.labs$ang)[which(nba.labs$ang < -90)]

Add a geom_text for labels:

p2 = ggplot(nba.m, aes(x=Name, y=var2, fill=value)) +
     geom_tile(colour="white") +
     geom_text(data=nba.labs, aes(x=Name, y=var2+1.5,
        label=Name, angle=ang, hjust=hjust), size=3) +
     scale_fill_gradient(low = "white", high = "steelblue") +
     ylim(c(0, max(nba.m$var2) + 1.5)) +
     scale_y_discrete(breaks=y_breaks, labels=y_labels) +
     coord_polar(theta="x") +
     theme(panel.background=element_blank(),
           axis.title=element_blank(),
           panel.grid=element_blank(),
           axis.text.x=element_blank(),
           axis.ticks=element_blank(),
           axis.text.y=element_text(size=5))
print(p2)