How to avoid label overlap in pie chart

问题

I have a problem with labeling percent in pie charts. Some labels are overlapped since the space is not enough to distinctively show them. Could you give me any solution? Also, I don't want to label zero percents.

data is like this:

  BRCA_R_Y_4<-          structure(list(Group = c("1. General", "1. General", "1. General", 
                            "1. General", "1. General", "1. General", "1. General", "2. Cancer", 
                            "2. Cancer", "2. Cancer", "2. Cancer", "2. Cancer", "2. Cancer", 
                            "2. Cancer", "3. Clinicians", "3. Clinicians", "3. Clinicians", 
                            "3. Clinicians", "3. Clinicians", "3. Clinicians", "3. Clinicians", 
                            "4. Researchers", "4. Researchers", "4. Researchers", "4. Researchers", 
                            "4. Researchers", "4. Researchers", "4. Researchers"), 


           Reasons = c( "1. Burdened by the cost", "2. Believe I would not develop breast cancer ", 
                        "3. I don’t have breast cancer yet (it won’t be too late to treat afterwards)", 
                        "4. Worried about the side effects", "5. Have childbirth plans", 
                        "6. Do not trust test result", "7. Other", "1. Burdened by the cost", 
                        "2. Believe I would not develop breast cancer ", "3. I don’t have breast cancer yet (it won’t be too late to treat afterwards)", 
                        "4. Worried about the side effects", "5. Have childbirth plans", 
                        "6. Do not trust test result", "7. Other", "1. Burdened by the cost", 
                        "2. Believe I would not develop breast cancer ", "3. I don’t have breast cancer yet (it won’t be too late to treat afterwards)", 
                        "4. Worried about the side effects", "5. Have childbirth plans", 
                        "6. Do not trust test result", "7. Other", "1. Burdened by the cost", 
                        "2. Believe I would not develop breast cancer ", "3. I don’t have breast cancer yet (it won’t be too late to treat afterwards)", 
                        "4. Worried about the side effects", "5. Have childbirth plans", 
                        "6. Do not trust test result", "7. Other"), 
           Percent = c(8.1130355515041,16.9553327256153, 57.0647219690064, 12.1239744758432, 2.91704649042844, 
                                                                                                                                           2.73473108477666, 0.0911577028258888, 3.85304659498208, 6.00358422939068, 
                                                                                                                                           73.7455197132617, 13.1720430107527, 0.896057347670251, 1.88172043010753, 
                                                                                                                                           0.448028673835125, 1.40845070422535, 2.8169014084507, 78.8732394366197, 
                                                                                                                                           2.8169014084507, 4.22535211267606, 0, 9.85915492957746, 1.63265306122449, 
                                                                                                                                           6.53061224489796, 71.8367346938775, 6.93877551020408, 6.12244897959184, 
                                                                                                                                           2.04081632653061, 4.89795918367347)) , row.names = c(NA, -28L) , class = c("tbl_df", 
                                                                                                                                                                                                                    "tbl", "data.frame"))

And the code that I used for generating the pie chart is the following and reference of this code is : ggplot, facet, piechart: placing text in the middle of pie chart slices

dat_pies4 <- left_join(BRCA_R_Y_4,
                       BRCA_R_Y_4 %>% 
                         group_by(Group) %>%
                         summarize(Cnt_total = sum(Percent))) %>%
  group_by(Group) %>%
  mutate(end_angle = 2*pi*cumsum(Percent)/Cnt_total, each pie slice
         start_angle = lag(end_angle, default = 0),  each pie slice
         mid_angle = 0.5*(start_angle + end_angle))  

rpie = 1
rlabel = 0.6 

 dat_pies4 <- mutate(dat_pies4,
                    hjust = ifelse(mid_angle>pi, 1, 0),
                    vjust = ifelse(mid_angle<pi/2 | mid_angle>3*pi/2, 0, 1))

rlabel = 1.05 * rpie # now we place labels outside of the pies

pie.4 <-
  ggplot(dat_pies4) + 
  geom_arc_bar(aes(x0 = 0, y0 = 0, r0 = 0, r = rpie,
               start = start_angle, end = end_angle, fill = Reasons))+
  geom_text(aes(x = rlabel*sin(mid_angle), y = rlabel*cos(mid_angle), label = paste0 (round(Percent), "%"),
                hjust = hjust, vjust = vjust)) +
  coord_fixed() +
  scale_x_continuous(limits = c(-1.5, 1.5), name = "", breaks = NULL, labels = NULL) +
  scale_y_continuous(limits = c(-1.5, 1.5), name = "", breaks = NULL, labels = NULL) +
  facet_grid(.~Group, switch = "both")+
  theme_void()+
  scale_fill_grey()+
  theme(legend.position="bottom", legend.direction="vertical", legend.margin = margin(30, 0, 10, 0))+
  theme(plot.title = element_text(size = 12, hjust = 0.5))+
  labs(title = "<why do not want RRM>")+
  guides (fill =  guide_legend (title.theme = element_text (face = "bold")))

pie.4

And the result was like this:

My expectation for the new pie chart is like the following but labels should be outside of the pies:

Source

回答1:

An easy way is to use the library ggrepel.

library(ggrepel)

And then replace:

geom_text

by:

geom_text_repel

来源：https://stackoverflow.com/questions/52960015/how-to-avoid-label-overlap-in-pie-chart

标签

label

pie-chart

overlap