使用因子作为您的x轴缩放时，更改x轴限制

Question

是否可以在两侧将x轴限制增加1。例如，在下面的图中可以将xlimits更改为3和9？即xlim(3,9)

p <- ggplot(mtcars, aes(factor(cyl), mpg)) 
p + geom_boxplot() 

当试图xlim()我得到：

Error: Discrete value supplied to continuous scale 

，当我尝试scale_x_continuous(limits = c(3,9))我得到：

Error in if (zero_range(from) || zero_range(to)) return(rep(mean(to), : 
    missing value where TRUE/FALSE needed 
In addition: Warning messages: 
1: In loop_apply(n, do.ply) : 
    no non-missing arguments to min; returning Inf 
2: In loop_apply(n, do.ply) : 
    no non-missing arguments to max; returning -Inf 
3: In loop_apply(n, do.ply) : 
    position_dodge requires constant width: output may be incorrect 

Answer 1

你想scale_x_discrete：

p <- ggplot(mtcars, aes(factor(cyl), mpg)) 
p + geom_boxplot() + scale_x_discrete(limits = c("4","6")) 

或xlim：

p <- ggplot(mtcars, aes(factor(cyl), mpg)) 
p + geom_boxplot() + xlim("4", "6") 

编辑：要求包括更宽的范围。要包括其他值，则需要使用中断功能，各种因素的列表：

p <- ggplot(mtcars, aes(factor(cyl), mpg)) 
p + geom_boxplot() + 
    scale_x_discrete(breaks = factor(3:9), limits = c("3", "4", "5", "6", "7", "8", "9")) 

在这种情况下，你必须绘制出了8缸箱线图，如果你不给假8：

p + geom_boxplot() + 
    scale_x_discrete(breaks=factor(c("3","4","5","6","7", "eight", "9")), 
        limits = c("3", "4", "5", "6", "7", "eight", "9") 

或绘图前筛选出来：

mtcars<-mtcars[mtcars$cyl!=8,] 

参考：scale_x_discrete