ggplot2 geom_boxplot 的用户定义参数

Question

我有以下data.frame：

df = data.frame(ymin = c(0.35,0.4,0.25,0.3,0.55,0.6), lower = c(0.45,0.5,0.35,0.4,0.65,0.7), middle = c(0.5,0.55,0.4,0.45,0.7,0.75), upper = c(0.55,0.6,0.45,0.5,0.75,0.8), ymax = c(0.65,0.7,0.55,0.6,0.85,0.9), factor = c("parental","parental","cross","cross","sex","sex"), factor.label = c("paternal","maternal","F1i","F1R","M","F"), posterior.probability = c(0.92,0.92,0.97,0.97,0.99,0.99), x = c(1,1,2,2,3,3), colors = c("blue","red","gray30","gray70","lightskyblue","pink"))

我想生成一个 ggplot2 箱线图，其中 df$x 定义框的 x 轴位置，df$lower、df$upper、df$middle、df$ymin、df$ymax 定义框，df$颜色定义框的颜色。正如你所看到的，每对盒子都应该放在同一个 x 轴位置。使用 alpha 参数，我将使框透明，因此重叠部分可见。

我目前拥有的是这段代码：

p = ggplot(beta.df, aes(x = x, color = colors))
p = p + geom_boxplot(aes(lower = lower,upper = upper, middle = middle, ymin = ymin, ymax = ymax, fill = colors), position = position_dodge(width = 0), width = 0.5, alpha = 0.5, stat = "identity")

显然，盒子的颜色搞砸了——"blue" 和 "red" 盒子应该在 df$x = 1，"gray30" 和 "gray70" 盒子应该在 df$x = 2，而 @ 987654330@ 和 "pink" 框应该在 df$x = 3。所以我正在寻找解决这个问题。

我还希望指定图例标题和标签，而不是默认生成。此外，对于每对具有相同 x 轴位置的框，df$posterior.probability 值是相同的，我想要在图的顶部绘制这些值（每对一个），比​​如最大 y 轴值，或在每对框的 max(ymax) 顶部和相应的 x 轴位置。换句话说，0.92、0.97 和 0.99 将分别绘制在 x 位置：1、2 和 3，以及绘图的最大 y 位置或这些位置 y 位置：0.75、0.65 和 0.95，分别。

Answer 1

您的箱线图是重叠的，正如我从您的代码中了解到的那样，您不希望这样。您的代码中不需要位置元素，您必须将x 视为一个因素，以便将它们彼此相邻绘制。

使用此代码：

ggplot(df, aes(x = as.factor(x), color = colors)) + 
  geom_boxplot(aes(lower = lower,upper = upper, middle = middle, ymin = ymin, ymax = ymax, fill = colors), width = 0.5, alpha = 0.5, stat = "identity") +
  geom_text(data = df, aes(x = as.factor(x), y = ymax, label = posterior.probability), size = 4, vjust = -0.5) +
  scale_fill_identity("Color legend", guide = "legend", labels = c("paternal","F1i","F1R","M","F","maternal")) +
  scale_color_identity("Color legend", guide = "legend", labels = c("paternal","F1i","F1R","M","F","maternal")) +
  labs(title = "Plot title", x = "X-lab label", y = "Y-lab label")

你会得到这个结果：

如果您不希望文本标签颜色相同，请将color = "black" 添加到geom_text 部分。

Answer 2

对于制作标签的新数据框，每个 x 位置仅包含一个标签，并且 y 值被计算为最大 ymax 值。

library(plyr)
df.text<-ddply(df,.(x),summarise,y=max(ymax),label=max(posterior.probability))

当您提供颜色名称时，您应该使用 scale_fill_identity() 和 scale_color_identity() 告诉 ggplot 将它们解释为实际颜色。如果需要显示图例，则将参数guide="legend" 添加到scale_fill_identity() 和scale_color_identity()，然后提供要在图例中显示的labels=。然后使用geom_text() 和新数据框在箱线图上方添加标签。

ggplot(df, aes(x = x)) + 
  geom_boxplot(aes(lower = lower,upper = upper, middle = middle, ymin = ymin, 
                    ymax = ymax,color = colors, fill = colors), 
                    position = position_dodge(width = 0), width = 0.5, 
                     alpha = 0.5, stat = "identity")+
  scale_fill_identity("Legend name",guide="legend",
                      labels=c("paternal","F1i","F1R","M","F","maternal"))+
    scale_color_identity("Legend name",guide="legend",
                      labels=c("paternal","F1i","F1R","M","F","maternal"))+
  geom_text(data=df.text,aes(x=x,y=y,label=label))