直方图颜色用R中的分类变量填充

Question

我正在尝试创建一个这样的情节：

qplot(carat, data = diamonds, geom = "histogram", fill = color)

然而，我没有使用x轴的定量变量，而是使用分类数据。我正在使用这样的数据框：

refBases=c("A","A","A","C","C","C","G","G","G","T","T","T")
altBases=c("C","G","T","A","G","T","A","C","T","A","C","G")
myDF$ref=refBases
myDF$alt=altBases
myDF$Freq=c(5,2,3,6,9,6,8,6,7,4,6,4)

所以，基本上，我希望我的情节看起来一样，只是x轴将是ref列的四个区（A，C，G，T）; y轴将是Freq;并且颜色图例将是alt列（A，C，G，T）中的四个变量。因此，基本上，x轴上将有四个参考箱，每个参考箱沿y轴分为三个部分，颜色图例表示alt值。

当我尝试我期望的时候，我得到一些相当愚蠢的东西：

qplot(ref,Freq,data=myDF,fill=alt)

Answer 1

你所描述的并不像直方图（这是连续随机变量估算核密度的一个非常具体的图）;听起来你只想要一个条形图。我相信这就是你要找的东西

myDF <- data.frame(
    ref=c("A","A","A","C","C","C","G","G","G","T","T","T"),
    alt=c("C","G","T","A","G","T","A","C","T","A","C","G"),
    Freq=c(5,2,3,6,9,6,8,6,7,4,6,4)
)

library(ggplot2)
ggplot(myDF, aes(ref, Freq, fill=alt)) + 
    geom_bar(stat="identity", position="dodge")