如何更改
ggplot()
图中线条的透明度(即直方图、线图等)?
例如考虑下面的代码:
data <- data.frame(a=rnorm(100), b = rnorm(100,.5,1.2))
data <- melt(data)
colnames(data) <- c("Category", "Intensity")
p <- ggplot(data, aes(x=Intensity))
p <- p + geom_density(aes(color=Category), size=2, alpha=.4)
print(p)
我期望这些线条是透明的(如
alpha=.4
),但事实并非如此。
只需遵循@baptiste的指示,
data <- data.frame(a=rnorm(100), b = rnorm(100,.5,1.2))
data <- melt(data)
colnames(data) <- c("Category", "Intensity")
p <- ggplot(data, aes(x=Intensity))
p + geom_line(aes(color=Category), stat="density", linewidth=2, alpha=0.4)