绘制F-测试与GGPLOT2

Question

的力量我想ggplot2绘制的F-test的power及以下MWE与图形输出：

library(ggplot2) 
df1 <- 3 
df2 <- 8 
Alpha <- 0.05 

df <- data.frame(X = seq(from = 0, to = 10, length = 500)) 

p <- ggplot(data=df, mapping=aes(x = X, y = df(x = X, df1 = df1, df2 = df2, ncp=0)))+ 
     geom_area(color="black", fill="white") 
p <- p + geom_area(aes(x=X, y=df(x = X, df1 = df1, df2 = df2, ncp=2)), color="blue", fill="blue", alpha = 1/3) 
p <- p + scale_y_continuous(expand = c(0, 0)) + scale_x_continuous(breaks=seq(0, 10, 1)) 
p <- p + geom_area(data = subset(df, X > qf(p = 1-Alpha, df1 = df1, df2 = df2, ncp=0)), fill = "red") 
p <- p + geom_area(data = subset(df, X > qf(p = 1-Alpha, df1 = df1, df2 = df2, ncp=0)), 
      aes(x=X, y=df(x = X, df1 = df1, df2 = df2, ncp=2)), fill = "green", alpha=1/3) 
p 

我不知道如何使它更加透明。不同的地区不是很清楚。任何建议将不胜感激。谢谢

Answer 1

在我看来，你应该定义要绘制第一，然后才开始绘制整个数据集。这是我会做的。

# load ggplot 
require(ggplot2) 
# define data 
df1 <- 3 
df2 <- 8 
Alpha <- 0.05 
X=seq(from = 0, to = 10, length = 500) 
# Define the data outside ggplot 
dd <- data.frame(x=c(X,X), 
       y=c(df(X, df1, df2, ncp=0), df(X, df1, df2, ncp=2)), 
       npc=factor(rep(c(0,2), each=length(X))), 
       quantile=c(X>qf(p = 1-Alpha, df1 = df1, df2 = df2, ncp=0), 
          # should this be qf(..., npc=0) or qf(..., npc=2)? 
          X>qf(p = 1-Alpha, df1 = df1, df2 = df2, ncp=2))) 
# Plot 
pp <- ggplot(data=dd, aes(x=x, ymin=0, ymax=y, fill=npc, color=npc, alpha=quantile)) 
pp <- pp + geom_ribbon() 
# Play with different alpha-ranges until you are satisfied 
pp + scale_alpha_discrete(range=c(.2, .5), guide="none") 

Answer 2

透明度通过alpha图形参数控制。只需将其设置为较低的值即可。现在你已经拥有它设置为1/3，尝试将其设置为1/6

library(ggplot2) 
df1 <- 3 
df2 <- 8 
Alpha <- 0.05 

df <- data.frame(X = seq(from = 0, to = 10, length = 500)) 

p <- ggplot(data=df, mapping=aes(x = X, y = df(x = X, df1 = df1, df2 = df2, ncp=0)))+ 
    geom_area(color="black", fill="white") 
p <- p + geom_area(aes(x=X, y=df(x = X, df1 = df1, df2 = df2, ncp=2)), color="blue", fill="blue", alpha = 1/6) ## this is the only line I've changed. 
p <- p + scale_y_continuous(expand = c(0, 0)) + scale_x_continuous(breaks=seq(0, 10, 1)) 
p <- p + geom_area(data = subset(df, X > qf(p = 1-Alpha, df1 = df1, df2 = df2, ncp=0)), fill = "red") 
p <- p + geom_area(data = subset(df, X > qf(p = 1-Alpha, df1 = df1, df2 = df2, ncp=0)), 
        aes(x=X, y=df(x = X, df1 = df1, df2 = df2, ncp=2)), fill = "green", alpha=1/3) 
p