Question

我想绘制一些数据，然后为平均值和平均值+/-标准差添加回归线和水平线，每个都有不同的颜色。我已经设法做到了这一点，但我无法正确传说。它显示前两个标签，但没有说明三条水平线。如何让图例也为这三行中的每一行添加标签？

另一篇文章提到show_guide = TRUE，但这对我没有用。我也一直在查看scale_colour_manual的文档，但这对我没有帮助。

我的代码是：

p <- qplot(mpg, wt, data = mtcars, colour="1")
p <- p + geom_smooth(method='lm',aes(x=mpg,y=wt,colour="2"),formula=y~x)
p <- p + geom_hline(yintercept = mean(mtcars$wt), colour = "3")
p <- p + geom_hline(yintercept = mean(mtcars$wt) + sd(mtcars$wt), colour = "3",    linetype="dashed")
p <- p + geom_hline(yintercept = mean(mtcars$wt) - sd(mtcars$wt), colour = "3", linetype="dashed")      
p <- p + labs(colour="")    
p <- p + scale_colour_manual(values = c("red","blue", "green","green","green"),labels=c("Data","Regression","Mean","Mean + SD","Mean - SD"))
p <- p + guides(colour = guide_legend())
print(p)

任何帮助将不胜感激，干杯！

Answer 1

我认为这可能更接近你想要的东西：

d <- data.frame(yint = c(mean(mtcars$wt) - sd(mtcars$wt),
                mean(mtcars$wt),
                mean(mtcars$wt) + sd(mtcars$wt)),
                grp = c('dashed','solid','dashed'))

p <- ggplot(data = mtcars,aes(mpg, wt)) + 
    geom_point(aes(color = "Data")) +
    geom_smooth(method='lm',aes(x=mpg,y=wt,color = "Regression"),formula=y~x) + 
    geom_hline(data = d,aes(yintercept = yint,linetype = grp,color = "Mean +/- SD")) + 
    scale_linetype_manual(values = c('dashed' = 'dashed','solid' = 'solid')) + 
    labs(color = "")
print(p)

关于分别标记每条水平线的问题，我的答案是它根本不属于传说。这些应标有geom_text()：

d <- data.frame(yint = c(mean(mtcars$wt) - sd(mtcars$wt),
                         mean(mtcars$wt),
                         mean(mtcars$wt) + sd(mtcars$wt)),
                         grp = c('dashed','solid','dashed'),
                         lab = c('-SD','Mean','+SD'))

p <- ggplot(data = mtcars,aes(mpg, wt)) + 
    geom_point(aes(color = "Data")) +
    geom_smooth(method='lm',aes(x=mpg,y=wt,color = "Regression"),formula=y~x) + 
    geom_hline(data = d,aes(yintercept = yint,linetype = grp),color = "green") + 
    geom_text(data = d,aes(y = yint,label = lab),
              vjust = -0.5,hjust = 1,x = Inf,size = 3) +
    scale_linetype_manual(values = c('dashed' = 'dashed','solid' = 'solid')) + 
    labs(color = "")
print(p)

Answer 2

Joran的回答激发了我做出一些改变，现在我已经设法写了一些代码，给了我正在寻找的情节和传奇：

n <- ncol(mtcars)
mtcars[,n+1] <- mean(mtcars$wt)
mtcars[,n+2] <- mean(mtcars$wt) + sd(mtcars$wt)
mtcars[,n+3] <- mean(mtcars$wt) - sd(mtcars$wt)
p <- qplot(mpg,wt,data = mtcars, colour="1")
p <- p + geom_smooth(method='lm',aes(x=mpg,y=wt,colour="2"),formula=y~x)
p <- p + geom_line(aes(x=mpg,y=mtcars[,n+1],colour="3"))
p <- p + geom_line(aes(x=mpg,y=mtcars[,n+2],colour="4"),linetype="dashed")
p <- p + geom_line(aes(x=mpg,y=mtcars[,n+3],colour="5"),linetype="dashed")
p <- p + labs(colour="")    
p <- p + scale_colour_manual(values = c("red","blue",  "green","green","green"),labels=c("Data","Regression","Mean","Mean + SD","Mean - SD"))
p <- p + guides(colour = guide_legend())
print(p)

ggplot缺少图例中的标签

2 个答案: