在Rggplot中，關于'geom_rect'極坐標的幾個問題

在 R ggplot 中，使用 'geom_rect' 可以生成下面的圖。現在，我有幾個問題：

1. 有什么辦法可以簡化當前的代碼嗎？
2. 如何在標簽中添加“數量”（目前僅包含“類別/子類別”）
3. “填充顏色”很難看，尤其是“sub_category”（可能使用相同的顏色，只需更改“alpha”引數）
4. 邊界不是很平滑（鋸齒狀邊框）

任何人都可以幫忙嗎？謝謝！

   library(tidyverse)
    
    test_data <- data.frame(category = c("retail","retail","retail","retail","retail","hotel"),
                            sub_category=c("retail_sub1","retail_sub2","retail_sub3","retail_sub4","retail_sub5","hotel"),
                          amount=c(51083.26,27454.13,22495.89,21195.05,16863.69,60210.6))
    
    test_data1 <- test_data %>% mutate(ymax=cumsum(amount),
                         ymin=lag(cumsum(amount),default=0))
    
    
    test_data1$y_category_position[test_data1$category=='retail'] <- 
      max(test_data1$ymax[test_data1$category=='retail'])/2
    
    
    test_data1$y_category_position[test_data1$category=='hotel'] <- 
      max(test_data1$ymax[test_data1$category=='retail']) 
      max(test_data1$ymax[test_data1$category=='hotel'])/6 # tried may times, seems 6 for divisor is better 
    
      test_data1 %>% ggplot() 
      # for category bar and label
      geom_rect(aes(xmin=3,xmax=6,ymin=ymin,ymax=ymax,fill=category)) 
      geom_text(aes(x=4.5,y=y_category_position,label=category)) 
      # for sub_category bar and label (exclude category 'hotel')
      geom_rect(data= test_data1 %>% filter(sub_category !='hotel'),
                aes(xmin=6,xmax=8,
                    ymin=ymin,ymax=ymax,fill=sub_category)) 
     geom_text(data= test_data1 %>% filter(sub_category !='hotel'),
               aes(x=7,y=(ymax ymin)/2,label=sub_category)) 
      coord_polar(theta = 'y') 
      theme_minimal()

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以后，請在每個帖子中提出 1 個問題。

逐條回答您的問題。

1. 這段代碼可以簡化嗎？

是的，您本質上有一個堆積條形圖，所以如果我們想要每個區域 1 個標簽，我們需要預先匯總資料，但不必費心預先計算累積和等。

library(tidyverse)

test_data <- data.frame(category = c("retail","retail","retail","retail","retail","hotel"),
                        sub_category=c("retail_sub1","retail_sub2","retail_sub3","retail_sub4","retail_sub5","hotel"),
                        amount=c(51083.26,27454.13,22495.89,21195.05,16863.69,60210.6))

barchart <- test_data %>%
  # Reshape data
  pivot_longer(-amount, names_to = "level", values_to = "name") %>%
  # Filter out the hotel subcategory, leaving in the (super)category
  filter(!(level == "sub_category" & name == "hotel")) %>%
  # Sum over category level and names
  group_by(level, name) %>%
  summarise(amount = sum(amount), .groups = "keep") %>%
  # Regular stacked bar chart code
  ggplot(aes(x = level, y = amount))  
  geom_col(aes(fill = name), width = 1)  
  geom_text(
    aes(label = paste0(name, "\n", amount), # <--- point 2
        group = interaction(name, level)),
    position = position_stack(vjust = 0.5),
  )
barchart

隨后，添加coord_polar()將在圓環圖中制作條形圖。

barchart   coord_polar(theta = "y")

^{由reprex 包(v2.0.1)于 2021 年 10 月 26 日創建}

2. 如何在標簽上添加“金額”？

您可以將其設定label = paste0(name, "\n", amount)為美學（請參閱代碼）。

3. “填充顏色”很難看。

查看scale_fill_*()離散調色板的函式系列。

4. 邊界不是很平滑。

That depends on the anti-aliasing for your graphics device. In RStudio you can set 'Tools > Global Options > General > Graphics > Backend > Select AGG' (or Cairo). For saving plots you could for example use ragg::agg_png().

標籤：r ggplot2

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