如何从饼图中进一步放置标签

Question

How to place the labels further away from pie chart in R?

slices <- c(10, 12, 4, 16, 8)
lbls <- c("US", "UK", "Australia", "Germany", "France")
pct <- round(slices/sum(slices)*100)
lbls <- paste(lbls, pct) # add percents to labels
lbls <- paste(lbls,"%",sep="") # ad % to labels
pie(slices,labels = lbls, col=rainbow(length(lbls)), radius=.2)

Answer 1

You can modify the pie -function line 50-54 and save it as a new function pie2

Type

pie

Change line 50-54 to

if (!is.na(lab) && nzchar(lab)) {
  lines(c(1, 1.35) * P$x, c(1, 1.35) * P$y)
  text(1.5 * P$x, 1.5 * P$y, labels[i], xpd = TRUE, 
       adj = ifelse(P$x < 0, 1, 0), ...)
}

Change line length (default = 1.05 )

  lines(c(1, 1.35) * P$x, c(1, 1.35) * P$y)

Change the factor (default = 1.1 )

  text(1.5 * P$x, 1.5 * P$y, labels[i], xpd = TRUE, 
       adj = ifelse(P$x < 0, 1, 0), ...)

Now define pie2 and run the new function

pie2(slices,labels = lbls, col=rainbow(length(lbls)), radius=.2)

Answer 2

You could manually place text with text() and create no labels by rep("",times).

But I agree, pie-charts are a bad way to visualize data.

To provide some code,

pie(slices,labels = rep("",5), col=rainbow(length(lbls)), radius=.8,lty=4)
text(0.9,0.6,"UK")
lines(c(0.6,0.85),c(0.45,0.55))

and align everything where you want it.

If you just want to create one single pie chart this is an option, but getting all those coordinates right can be very frustrating..

Sorry I would have commented rather then answered if I had the option.

Answer 3

You can use ggplot to form the pie-chart. This will get the labels separate from the pie-chart as a legend.

# R version 3.2.2
install.packages("ggplot2") 
library("ggplot2")
slices <- c(10, 12, 4, 16, 8)
lbls <- c("US", "UK", "Australia", "Germany", "France")
pct <- round(slices/sum(slices)*100)
lbls <- paste(lbls, pct) # add percents to labels
lbls <- paste(lbls,"%",sep="") # ad % to labels
df = data.frame(slices = slices,labels =  lbls)
ggplot(df,aes(x = factor(1),fill = labels))+
        geom_bar(width = 1)+
        coord_polar(theta = "y")+
        theme(axis.title = element_blank())