ggplot2 - 來自數值/整數數據的離散X軸值

Question

我有一些數據，我正在嘗試使用ggplot2進行圖形化，其中x軸是數值/整數值。繪製圖形時，我希望圖形只顯示數據集中存在的x的值，而不會將值添加到x軸（離散值）。下面的完全可重現的示例演示了這個問題：即使提供的x軸值爲1,3,25，生成的圖形在x軸上呈現0,5,15,20,25。我嘗試過鑄造這些價值觀，以及嘗試一種獨立的規模，但沒有一個似乎有效。

編輯儘管x軸上的值是數字/整數，但它們代表因素（即試驗中的人數，發動機中的汽缸數等）並且不是連續值。

#Example 
library(ggplot2) 

row1 <- c(1, 1) 
row2 <- c(3, 2) 
row3 <- c(25, 10) 

data <- data.frame() 
data <- rbind(data, row1) 
data <- rbind(data, row2) 
data <- rbind(data, row3) 
names(data) <- c("A", "B") 

qplot(A, B, data = data, geom="line") 


#Things Tried 
qplot(factor(A), B, data = data, geom="line") #geom_path: Each group consist of only one observation. Do you need to adjust the group aesthetic? 
qplot(as.factor(A), B, data = data, geom="line") #geom_path: Each group consist of only one observation. Do you need to adjust the group aesthetic? 
qplot(character(A), B, data = data, geom="line") #Error in character(A) : invalid 'length' argument 
qplot(as.character(A), B, data = data, geom="line") #geom_path: Each group consist of only one observation. Do you need to adjust the group aesthetic? 
qplot(A, B, data = data, geom="line") + scale_x_discrete(breaks = data$A) #Works, but values are too far apart 

Answer 1

這是你在追求什麼？

#START WITH SAMPLE DATA SET AS PER QUESTION 
library(ggplot2) 
row1 <- c(1, 1) 
row2 <- c(3, 2) 
row3 <- c(25, 10) 

data <- data.frame() 
data <- rbind(data, row1) 
data <- rbind(data, row2) 
data <- rbind(data, row3) 
names(data) <- c("A", "B") 

#PRODUCE SOLUTION, MODIFY DATASET 
df <- data 
df$id <- 1:nrow(df) 
df$Labels <- as.factor(df[,"A"]) 

#RENDER PLOT 
ggplot(df,aes(id,B)) + 
    geom_path() + 
    scale_x_continuous(breaks=df$id,labels=df$Labels) + 
    labs(x="A") 

#EQUIVALENT QPLOT CODE: 
qplot(id, B, data = df, geom="line") + 
    scale_x_continuous(breaks = df$id,labels=df$Labels) + 
    labs(x="A") 

將會產生以下結果：

對於什麼是值得的，我個人認爲你的數據誤導了上面的介紹，並會傾向於代表它以下列方式：

ggplot(df,aes(id,B)) + 
    geom_bar(stat="identity",aes(fill=Labels),color="black") + 
    scale_x_continuous(breaks=df$id,labels=paste("Trial:",df$Labels)) + 
    labs(x="A",fill="Trial Number",title="Trial XYZ Results") + 
    theme_bw() + 
    theme(legend.position=c(0,1),legend.justification=c(0,1))