Wrapping / bending a text around a circle in plot (R)

Question

Is there any chance to write text which is \"wrapped\" around the circle? I mean something like this:

Answer 1

You may also try arctext in plotrix package:

library(plotrix)

# set up a plot with a circle
plot(x = 0, y = 0, xlim = c(-2, 2), ylim = c(-2, 2))
draw.circle(x = 0, y = 0, radius = 1)

# add text
arctext(x = "wrap some text", center = c(0, 0), radius = 1.1, middle = pi/2)
arctext(x = "counterclockwise", center = c(0, 0), radius = 1.1, middle = 5*pi/4,
        clockwise = FALSE, cex = 1.5)
arctext(x = "smaller & stretched", center = c(0, 0), radius = 1.1, middle = 2*pi ,
        cex = 0.8, stretch = 1.2)

For greater opportunities of customization (an understatement; see the nice vignettes), you may have a look at circlize package. By setting facing = "bending" in circos.text, the text wraps around a circle.

library(circlize)

# create some angles, labels and their corresponding factors
# which determine the sectors 
deg <- seq(from = 0, to = 300, by = 60)
lab <- paste("some text", deg, "-", deg + 60)   
factors <- factor(lab, levels = lab)

# initialize plot
circos.par(gap.degree = 10)
circos.initialize(factors = factors, xlim = c(0, 1))
circos.trackPlotRegion(ylim = c(0, 1))

# add text to each sector  
lapply(factors, function(deg){
  circos.updatePlotRegion(sector.index = deg, bg.col = "red")
circos.text(x = 0.5, y = 0.5, labels = as.character(deg), facing = "bending")
})
circos.clear()

Update:
In circlize version 0.2.1, circos.text has two new options: bending.inside which is identical to original bending and bending.outside (see fig 11 in the vignette). Thus, it is easy to turn the text in the bottom half of the plot using bending.outside:

circos.par(gap.degree = 10)
circos.initialize(factors = factors, xlim = c(0, 1))
circos.trackPlotRegion(ylim = c(0, 1))

lapply(factors[1:3], function(deg){
  circos.updatePlotRegion(sector.index = deg, bg.col = "red")
  circos.text(x = 0.5, y = 0.5, labels = as.character(deg), facing = "bending.outside")
})

lapply(factors[4:6], function(deg){
  circos.updatePlotRegion(sector.index = deg, bg.col = "red")
  circos.text(x = 0.5, y = 0.5, labels = as.character(deg), facing = "bending.inside")
})
circos.clear()