使用facet_grid，geom_density和stat_function在ggplot中对图例进行Orgonize

Question

我有这段代码：

require(ggplot2)
require(scales)

Dataset = data.frame(Data = rnorm(100), Factor = c(rep("A",10), rep("B",10)))
graf <- ggplot(data = Dataset, aes(x=Data, fill=..x..)) +   
        geom_histogram(aes(x = Data, y=..density..), binwidth=0.6) + 
        facet_grid(Factor ~ .) + 
        geom_density(aes(x = Data, y=..density..), alpha=.2, fill='red', linetype="dotted", size=1.05) +
        stat_function(fun = dnorm, arg = list(mean = mean(Dataset$Data), sd = sd(Dataset$Data)), colour = "blue", size=1.07, guide = "Normal") +
        scale_fill_gradient(low = "grey25", high = "white") 

现在，我想组织图例：删除“x”图例并添加stat_function和geom_density的图例。我怎么能这样做？我尝试使用scale_color_manual，但它不起作用。

谢谢！

编辑：

这样就解决了：

Data = c(rnorm(50), rnorm(50))
Dataset = data.frame(Data = Data, Factor = c(rep("A",50), rep("B",50)), DensNormal = dnorm(Data, mean(Data), sd(Data)))
graf <- ggplot(data = Dataset, aes(Data, fill=..x..)) +     
        geom_histogram(aes(x = Data, y=..density..), binwidth=0.6) + 
        facet_grid(Factor ~ .) + 
        geom_density(aes(x = Data, y=..density.., colour="dens"), alpha=.2, fill='red', linetype="dotted", size=1.05) +
        geom_line(aes(y=DensNormal, colour = 'blue'),line = 1, size=1.07) +
        scale_fill_gradient(low = "grey25", high = "white") +
        scale_colour_manual(values = c('blue','black'),name = 'Density', labels = c('Normal','Nonparametric'))+
        guides(fill=FALSE)

现在我只想让传奇的背景在两者上都不是“红色”，因为它只是在非参数线上。任何想法如何？

谢谢！