ggplot2 - 数值/整数数据的离散X轴值

Question

我有一些数据，我试图使用ggplot2绘制图形，其中x轴是数值/整数值。绘制图形时，我希望图形仅显示数据集中存在的x值，而不是向x轴添加值（离散值）。下面完全可重现的示例演示了问题：即使提供的x轴值为1,3,25，结果图在x轴上呈现0,5,15,20,25。我已经尝试过铸造这些值，并尝试使用离散比例，但它们似乎都没有效果。

编辑虽然x轴上的值是数字/整数，但它们代表因子（即试验中的人数，引擎中的气缸数等）并且不连续值。

#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

这就是你想要的吗？

#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")

产生以下结果：

对于它的价值，我个人认为上述数据的呈现具有误导性，并倾向于以下列方式表示：

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))