如何使用ggplot表示分类变量与连续变量？

Question

I have to plot categorical variable flag having values Y and N against continuous variable Weight . Which is best kind of plot?

qplot(x=Data$Weight, geom="histogram", main = "Weight distribution for Y Goods", binwidth = 0.5, xlab = "Weight of Y Goods", fill=I("blue"), col=I("red"), alpha=I(0.2), xlim=c(0,5))

Answer 1

try adding fill = Data$Buy_Flag so your plot code looks like this:

qplot(
  x = Data$Weight,
  fill = Data$Buy_Flag,
  geom = "histogram",
  main = "Weight distribution for Y Goods",
  binwidth = 0.5,
  xlab = "Weight of Y Goods",
  fill = I("blue"),
  col = I("red"),
  alpha = I(0.2),
  xlim = c(0, 5)
)

and your graph looks like this: