基於數據幀列的Y軸ggplot盒圖

Question

我用ggplot創建了盒子圖，但是我想根據我使用匯總統計創建的不同數據框中列的順序來更改y軸的順序。

這是腳本。腳本下面是對我所需輸出的描述。

#data 
df <- data.frame(City = c("NY", "AMS", "BER", "PAR", "NY", "AMS", "AMS", "PAE"), 
      Time_Diff = c(4, 2, 7, 9, 2, 1, 10, 9), 
      Outliers = c(0, 0, 0, 0, 0, 1, 1, 0)) 

#data summary 
summary <- df %>% 
     group_by(City) %>% 
     summarise(Median = median(Time_Diff), 
     IQR = IQR(Time_Diff), 
     Outliers = sum(Outliers)) %>% 
     arrange(desc(Median), desc(IQR), desc(Outliers)) 

summary <- as.data.frame(summary) 


# Create ggplot object 
bp <-ggplot(data = df, aes(x = reorder(City, Time_Diff, FUN = median), y= Time_Diff)) # Creates boxplots 

# Create boxplot figure 
bp + 
    geom_boxplot(outlier.shape = NA) + #exclude outliers to increase visibility of graph 
    coord_flip(ylim = c(0, 25)) + 
    geom_hline(yintercept = 4) + 
    ggtitle("Time Difference") + 
    ylab("Time Difference") + 
    xlab("City") + 
    theme_light() + 
    theme(panel.grid.minor = element_blank(), 
    panel.border = element_blank(), #remove all border lines 
    axis.line.x = element_line(size = 0.5, linetype = "solid", colour = "black"), #add x-axis border line 
    axis.line.y = element_line(size = 0.5, linetype = "solid", colour = "black")) #add y-axis border line 

我想是y軸（翻轉的x軸）的順序是相同的，如發明內容數據幀City列的順序。這意味着：

從上到下：PAE，PAR，BER，NY，AMS

任何有效的和優雅的建議？

SOLUTION

謝謝Prradep，我用您的解決方案的腳本和它的作品。我稍微調整了它，這樣我就不必再次鍵入軸的值。我重新使用了數據框中的城市矢量。這是我使用的腳本：

#data 
df <- data.frame(City = c("NY", "AMS", "BER", "PAR", "NY", "AMS", "AMS", "PAE"), 
      Time_Diff = c(4, 2, 7, 9, 2, 1, 10, 9), 
      Outliers = c(0, 0, 0, 0, 0, 1, 1, 0)) 

#data summary 
summary <- df %>% 
    group_by(City) %>% 
    summarise(Median = median(Time_Diff), 
     IQR = IQR(Time_Diff), 
     Outliers = sum(Outliers)) %>% 
    arrange(desc(Median), desc(IQR), desc(Outliers)) 

summary <- as.data.frame(summary) 

# Preproces data for figure 
order_city <- summary$City 

# Create ggplot object 
bp <-ggplot(data = df, aes(x = reorder(City, Time_Diff, FUN = median), y= Time_Diff)) # Creates boxplots 

# Create boxplot figure 
bp + 
    geom_boxplot(outlier.shape = NA) + #exclude outliers to increase visibility of graph 
    coord_flip(ylim = c(0, 25)) + 
    geom_hline(yintercept = 4) + 
    ggtitle("Time Difference") + 
    ylab("Time Difference") + 
    xlab("City") + 
    theme_light() + 
    theme(panel.grid.minor = element_blank(), 
    panel.border = element_blank(), #remove all border lines 
    axis.line.x = element_line(size = 0.5, linetype = "solid", colour = "black"), #add x-axis border line 
    axis.line.y = element_line(size = 0.5, linetype = "solid", colour = "black")) + #add y-axis 
    scale_x_discrete(limits = rev(order_city)) #this is the function to change the order of the axis 

Answer 1

添加scale_x_discrete(limits = rev(c('PAE', 'PAR', 'BER', 'NY', 'AMS')))會做詭計。

---

這是你在找什麼：

# Create ggplot object 
bp <-ggplot(data = df, aes(x = reorder(City, Time_Diff, FUN = median), y= Time_Diff)) # Creates boxplots 

# Create boxplot figure 
bp + 
    geom_boxplot(outlier.shape = NA) + #exclude outliers to increase visibility of graph 
    coord_flip(ylim = c(0, 25)) + 
    geom_hline(yintercept = 4) + 
    ggtitle("Time Difference") + 
    ylab("Time Difference") + 
    xlab("City") + 
    theme_light() + 
    theme(panel.grid.minor = element_blank(), 
     panel.border = element_blank(), #remove all border lines 
     axis.line.x = element_line(size = 0.5, linetype = "solid", colour = "black"), #add x-axis border line 
     axis.line.y = element_line(size = 0.5, linetype = "solid",  colour = "black")) + #add y-axis border line 
    scale_x_discrete(limits = rev(c('PAE', 'PAR', 'BER', 'NY', 'AMS')))