[問題] ggplot繪製圓餅圖問題

[jackylikebmw (Tsai Chia Yu)]

[問題類型]:

程式諮詢(我想用R 做某件事情，但是我不知道要怎麼用R 寫出來)

[軟體熟悉度]:
使用者(已經有用R 做過不少作品)

[問題敘述]:
我目前想要透過ggplot繪製圓餅圖，上網看了很多範例
但是發現套用到我的檔案上時，在圖上繪製百分比時會出現錯誤
好像是當有較大百分比位數時，會有一些錯誤，想要請各位幫忙~

[程式範例]:
#以下為stackoverflow範例
#https://stackoverflow.com/questions/45657990
library(dplyr)
library(ggplot2)
data <-
data.frame(a=c("a1","a1","a2","a3","a1","a2","a3","a4",
"a2","a1","a5","a4","a3"),b=1:13)
data <- data %>%
  group_by(a) %>%
  count() %>%
  ungroup() %>%
  mutate(per=`n`/sum(`n`)) %>%
  arrange(per)
data$label <- scales::percent(data$per)
ggplot(data=data)+
  geom_bar(aes(x="", y=per, fill=a), stat="identity", width = 1)+
  coord_polar("y", start=0)+
  theme_void()+
  geom_text(aes(x=1, y = cumsum(per) - per/2, label=label))
#在這個範例中，程式是正常顯示的
# https://imgur.com/85FnFOr
#但是當我將某一比例加大時，畫圖就出現錯誤
library(dplyr)
library(ggplot2)
data <-
data.frame(a=c("a1","a1","a2","a3","a1","a2","a3","a4",
"a2","a1","a5","a4",rep("a3",20)),b=1:32)
data <- data %>%
        group_by(a) %>%
        count() %>%
        ungroup() %>%
        mutate(per=`n`/sum(`n`)) %>%
        arrange(per)
data$label <- scales::percent(data$per)
ggplot(data=data)+
        geom_bar(aes(x="", y=per, fill=a), stat="identity", width = 1)+
        coord_polar("y", start=0)+
        theme_void()+
        geom_text(aes(x=1, y = cumsum(per) - per/2, label=label))
#https://imgur.com/7BHUOuq

[環境敘述]:
R version 3.4.4 (2018-03-15)
Platform: x86_64-w64-mingw32/x64 (64-bit)
Running under: Windows >= 8 x64 (build 9200)
dplyr_0.7.4
ggplot2_2.2.1


[關鍵字]:
ggplot , piechart , 圓餅圖

--
※ 發信站: 批踢踢實業坊(ptt.cc), 來自: 1.172.82.96
※ 文章網址: https://www.ptt.cc/bbs/R_Language/M.1523958970.A.484.html
推 F0011010101: 一個方式是 把 %>% arrange(per)拿掉,就是不要排序
→ F0011010101: 然後把geom_text的地方 y=1-( cumsum(per) - per/2 )
→ F0011010101: 你會發現 雖然你前面用per對資料排序
→ F0011010101: 但fill=a的順序 還是照a1,a2,a3這樣的順序
→ celestialgod: https://goo.gl/U6DTQn
→ celestialgod: 感覺是你後面算y出錯
→ celestialgod: 試著不要在算一次，前面算完
→ F0011010101: 如果堅持要保留arrange(per) 那geom_bar的地方要改成
→ F0011010101: fill = ordered(a, levels = a)
→ F0011010101: 如果比例想要順時針遞增 arrange(desc(per))反過來排
→ F0011010101: 總之 不管怎樣 geom_text的y應該是一定要改的
→ jackylikebmw: 感謝回應~