Ggplot2 pie plot with geom_text_repel

Question

I draw some graphical charts with ggplot2 and succeeded in getting the labels put in the correct positions, since:

df <- data.frame(annotation=rep(c("promoter", "intergenic", "intragene", "5prime", "3prime"), 3), value=c(69.5, 16, 10.7, 2.5, 1.3, 57.2, 18.8, 20.2, 2.1, 1.7, 50.2, 32.2, 15.3, 1.2, 1.1), treatment=rep(c("treated1", "treated2", "untreated"), c(5, 5, 5)))

library(ggplot2)

ggplot(data = df, aes(x = "", y = value, fill = annotation)) + 
geom_bar(stat = "identity") +
geom_text(aes(label = value), position = position_stack(vjust = 0.5)) +
coord_polar(theta = "y") +
facet_grid(.~treatment)

Then I wanted to use ggrepel so that the numbers of small fragments did not overlap:

library(ggrepel)

ggplot(data = df, aes(x = "", y = value, fill = annotation)) + 
geom_bar(stat = "identity") +
geom_text_repel(aes(label = value), position = position_stack(vjust = 0.5)) +  
coord_polar(theta = "y") +
facet_grid(.~treatment)

But I get the following warning "Warning: ignoring unknown parameters: position"

and spoiled tags.

Does anyone know how to combine proper label positioning with geom_text_repel or any alternative?

Thank!

sessionInfo()
R version 3.3.2 (2016-10-31)
Platform: x86_64-redhat-linux-gnu (64-bit)
Running under: Scientific Linux 7.2 (Nitrogen)

locale:
 [1] LC_CTYPE=en_US.UTF-8       LC_NUMERIC=C              
 [3] LC_TIME=en_US.UTF-8        LC_COLLATE=en_US.UTF-8    
 [5] LC_MONETARY=en_US.UTF-8    LC_MESSAGES=en_US.UTF-8   
 [7] LC_PAPER=en_US.UTF-8       LC_NAME=C                 
 [9] LC_ADDRESS=C               LC_TELEPHONE=C            
 [11] LC_MEASUREMENT=en_US.UTF-8 LC_IDENTIFICATION=C       

attached base packages:
[1] stats     graphics  grDevices utils     datasets  methods   base     

other attached packages:
[1] ggrepel_0.6.5 ggplot2_2.2.1 limma_3.26.9 

loaded via a namespace (and not attached):
 [1] Rcpp_0.12.8      digest_0.6.12    grid_3.3.2       plyr_1.8.4      
 [5] gtable_0.2.0     magrittr_1.5     scales_0.4.1     stringi_1.1.5   
 [9] reshape2_1.4.2   lazyeval_0.2.0   labeling_0.3     tools_3.3.2     
 [13] stringr_1.2.0    munsell_0.4.3    colorspace_1.3-2 tibble_1.3.0    

Answer 1

First, you need to make the correct column with the position of your shortcuts before coord_polar(). I would do it with dplyr, but you can use whatever is convenient for you:

library('dplyr')

df <- df %>% 
  arrange(treatment, desc(annotation)) %>% 
  group_by(treatment) %>% 
  mutate(text_y = cumsum(value) - value/2)

df

# A tibble: 15 x 4
# Groups:   treatment [3]
   annotation value treatment text_y
        <chr> <dbl>     <chr>  <dbl>
 1   promoter  69.5  treated1  34.75
 2  intragene  10.7  treated1  74.85
 3 intergenic  16.0  treated1  88.20
 4     5prime   2.5  treated1  97.45
 5     3prime   1.3  treated1  99.35
 6   promoter  57.2  treated2  28.60
 7  intragene  20.2  treated2  67.30
 8 intergenic  18.8  treated2  86.80
 9     5prime   2.1  treated2  97.25
10     3prime   1.7  treated2  99.15
11   promoter  50.2 untreated  25.10
12  intragene  15.3 untreated  57.85
13 intergenic  32.2 untreated  81.60
14     5prime   1.2 untreated  98.30
15     3prime   1.1 untreated  99.45

, text_y y geom_text().

coord_polar():

ggplot(data = df, aes(x = "", y = value, fill = annotation)) + 
  geom_bar(stat = "identity") +
  geom_label(aes(label = value, y = text_y)) +
  facet_grid(.~treatment)

label_repel :

ggplot(data = df, aes(x = "", y = value, fill = annotation)) +
  geom_bar(stat = "identity") +
  geom_label_repel(aes(label = value, y = text_y)) +
  facet_grid(. ~ treatment) +
  coord_polar(theta = "y")