Ggplot2: geom_text() 添加额外的、不需要的值来绘制

Question

我有一个看似简单但无法解决的问题：plot 上出现了太多值。我只想查看总计数（tot_q，即 n）一次，以及相关的 pc（质量为 1 的类别的百分比).这是我的示例代码：

category <- as.factor(c(1, 2, 3, 3, 2, 2, 1, 2, 4, 4, 1, 3, 2, 2, 2, 1))
quality <- as.factor(c(0, 1, 1, 0, 0, 0, 1, 0, 0, 1, 1, 1, 0, 0, 1, 1))
mydata <- data.frame(category, quality)

mydata2<- mydata %>% group_by(category,quality) %>% mutate(count_q = n()) %>%
  group_by(category) %>% mutate(tot_q=n(),pc=count_q*100/tot_q)

myplot <- ggplot(mydata2, aes(x= category, y = pc)) +
  geom_bar(position = 'dodge', stat='identity', fill="lightblue") +
  geom_text(aes(label=round(pc)), position=position_dodge(0.9), vjust=-0.5) +
  geom_text(aes(label=round(tot_q)), nudge_y = 15, col="red")

myplot

问题：为什么我得到两次 tot_q 值（红色数字）？此外，我如何隐藏较低的百分比（例如，在类别 1 中我只想看到 75%）？我想这与我对数据的预处理有关，但我不知道该怎么做。

Answer 1

使用 geom_text()

的子集数据 (quality = 1)

library(ggplot2)
library(dplyr)
category <- as.factor(c(1, 2, 3, 3, 2, 2, 1, 2, 4, 4, 1, 3, 2, 2, 2, 1))
quality <- as.factor(c(0, 1, 1, 0, 0, 0, 1, 0, 0, 1, 1, 1, 0, 0, 1, 1))
mydata <- data.frame(category, quality)

mydata2<- mydata %>% group_by(category,quality) %>% mutate(count_q = n()) %>%
  group_by(category) %>% mutate(tot_q=n(),pc=count_q*100/tot_q)

myplot <- ggplot(mydata2, aes(x= category, y = pc)) +
  geom_bar(position = 'dodge', stat='identity', fill="lightblue") +
  geom_text(data = filter(mydata2, quality == 1),
    aes(label=round(pc)), position=position_dodge(0.9), vjust=-0.5) +
  geom_text(data = filter(mydata2, quality == 1),
    aes(label=round(tot_q)), nudge_y = 15, col="red")

myplot

^{由 reprex package (v0.3.0)}

于 2020-04-21 创建

Answer 2

这就是你想要的吗？ : filter(quality == 1) 在您的数据操作结束时。

library(ggplot2)
library(dplyr)

mydata2<- 
  mydata %>% 
  group_by(category, quality) %>% 
  mutate(count_q = n()) %>%
  group_by(category) %>% 
  mutate(tot_q = n(),
         pc = count_q * 100 / tot_q)%>% 
  filter(quality == 1)

myplot <- 
  ggplot(mydata2, aes(x= category, y = pc)) +
  geom_bar(position = 'dodge', stat='identity', fill="lightblue") +
  geom_text(aes(label = round(pc)), position=position_dodge(0.9), vjust = -0.5) +
  geom_text(aes(label = round(tot_q)), nudge_y = 15, col = "red")

myplot

Ggplot2: geom_text() 添加额外的、不需要的值来绘制

Ggplot2: geom_text() adds additional, unwanted values to plot

r

ggplot2

geom-text