How to remove select labels in ggplot geom_bar plot and center these labels?-CodePudding

Is it possible to remove certain/specific labels from geom_bar ggplot (geom_text) for repeated values and center this value on the plot/bars?

My data:

structure(list(prey_name = c("Amphipod", "Byths", "Chiro.Adult", 
"Chiro.Larvae", "Chiro.Pupae", "Chironomidae", "Chydoridae", 
"Copepoda", "Cyclopoid", "Daphnia", "Dreissena", "EggMass", "Eurycercidae", 
"Fish.Eggs", "Goby", "Hemimysis", "Isopod", "Sphaeriidae", "Trichopteran", 
"UID.Fish"), Fi = c(0.189473684210526, 0.515789473684211, 0.0526315789473684, 
0.157894736842105, 0.252631578947368, 0.0526315789473684, 0.0105263157894737, 
0.0210526315789474, 0.0105263157894737, 0.147368421052632, 0.0842105263157895, 
0.0210526315789474, 0.0210526315789474, 0.0105263157894737, 0.147368421052632, 
0.0105263157894737, 0.0947368421052632, 0.0421052631578947, 0.0105263157894737, 
0.0210526315789474)), class = c("tbl_df", "tbl", "data.frame"
), row.names = c(NA, -20L))

My plot:

ggplot(FO_adult, aes(x=reorder(prey_name, -Fi), Fi, fill=prey_name))  
  geom_bar(stat = "identity")  
  geom_text(aes(y = Fi, label = round(Fi, digits=3)), vjust = -0.5,
            check_overlap = TRUE)  
  ggtitle("Frequency of Occurrence")  
  labs(x="Prey", fill = "Prey Name", y = "Frequency of Occurrence (%)", 
       caption = "Source: DNR Diet Data")   
  scale_fill_igv(palette = "default")  
  theme_bw()  
  theme(legend.position = "right", 
        plot.title = element_text(hjust=0.5),
        legend.background = element_rect(fill = "white", color = 1),
        axis.text.x = element_blank(),
        axis.ticks.x = element_blank(),
        axis.ticks.length = unit(0.2,"cm"))  
  scale_y_continuous(expand = expansion(mult = c(0,0.1)))

Which gives:

My question is, is it possible to just have one label for the values that repeat? For example, 0.147 occurs twice (Daphnia and Goby); 0.053 for other prey; 0.021, etc. Can I have these values on the plot just once and have it centered?

Desired plot:

I know I could subset and do something like this:

ggplot(FO_adult, aes(x=reorder(prey_name, -Fi), Fi, fill=prey_name))  
  geom_bar(stat = "identity")  
  geom_text(data = subset(FO_adult, Fi > 0.10), 
              aes(y = Fi, label = round(Fi, digits=3)), vjust = -0.5)  
  ggtitle("Frequency of Occurrence")  
  labs(x="Prey", fill = "Prey Name", y = "Frequency of Occurrence (%)", 
       caption = "Source: DNR Diet Data")   
  scale_fill_igv(palette = "default")  
  theme_bw()  
  theme(legend.position = "right", 
        plot.title = element_text(hjust=0.5),
        legend.background = element_rect(fill = "white", color = 1),
        axis.text.x = element_blank(),
        axis.ticks.x = element_blank(),
        axis.ticks.length = unit(0.2,"cm"))  
  scale_y_continuous(expand = expansion(mult = c(0,0.1)))

which removes labels for values that are less than 10%, but I would prefer to keep the others if possible...

I looked at the following SO posts but did not really answer my question:

CodePudding user response：

This is not exactly the desired output. But we could manipulate the values for geom_text:

library(tidyverse)
library(ggsci)
FO_adult %>% 
  arrange(-Fi) %>% 
  group_by(Fi) %>% 
  mutate(x = ceiling(max(row_number()/2))) %>% 
  mutate(Fi_new = ifelse(x == row_number(), Fi, NA_real_)) %>% 
  ggplot(aes(x=reorder(prey_name, -Fi), Fi, fill=prey_name))  
  geom_bar(stat = "identity")  
  geom_text(aes(y = Fi, label = round(Fi_new, digits=3)), vjust = -0.5,
            check_overlap = TRUE)  
  ggtitle("Frequency of Occurrence")  
  labs(x="Prey", fill = "Prey Name", y = "Frequency of Occurrence (%)", 
       caption = "Source: DNR Diet Data")   
  scale_fill_igv(palette = "default")  
  theme_bw()  
  theme(legend.position = "right", 
        plot.title = element_text(hjust=0.5),
        legend.background = element_rect(fill = "white", color = 1),
        axis.text.x = element_blank(),
        axis.ticks.x = element_blank(),
        axis.ticks.length = unit(0.2,"cm"))  
  scale_y_continuous(expand = expansion(mult = c(0,0.1)))