将图例添加到具有不同类型美学的ggplot直方图中

Question

我想在其中一个地块上添加图例，但是我有不同的审美观，并且我从未创建过图例，因此我很难确定如何构建图例。

我的审美观之一是填充代码，我将其手动添加为矢量。另一种美学是我在geom_vline中添加的垂直线。

从下面的图形中，我想添加到图例中的三个特征：1）颜色为深蓝色的条，2）颜色为浅蓝色的条，以及3）垂直线。

有人对我有建议如何有效地编码吗？

#df
df <- data.frame(Time_Diff <- runif(1000, 0, 200))


# Show median, IQR range and outliers
colors <- c(rep("blue",3), rep("paleturquoise2",38))
bp_overall <- ggplot(data = df, aes(Time_Diff)) 
bp_overall + 
  geom_histogram(binwidth = 5, fill = colors) + #create histogram
  ggtitle("Time Difference")  +
  xlab("Time in Days") +
  ylab("Amount") +
  geom_vline(xintercept = 3, linetype = "twodash", size = 1,      colour= "darkblue") + #show median
  scale_x_continuous(breaks = seq(0, 202, 10)) +
  theme_light() +
  theme(panel.grid.minor = element_blank(),
    panel.border = element_blank(), #remove all border lines
    axis.line.x = element_line(size = 0.5, linetype = "solid", colour = "black"), #add x-axis border line
    axis.line.y = element_line(size = 0.5, linetype = "solid", colour = "black")) + #add y-axis border line
  theme(plot.title = element_text(family = windowsFont("Verdana"),     color="black", size=14, hjust = 0.5)) +
  theme(axis.title = element_text(family = windowsFont("Verdana"), color="black", size=12)) 

在Djork的建议之后，我进入了以下脚本，该脚本有效，我很满意。我现在要完成的唯一一件事就是使图例成为一个整体（直方图图例和行图例合并为一个连贯的整体）。有人有建议吗？

# reformat data
set.seed(1)
df <- data.frame(runif(1000, 0, 200))
colnames(df) <- "Time_Diff"

bp_overall + 
  geom_histogram(data = subset(df, Time_Diff <= 12.5), aes(x = Time_Diff, fill="BAR BLUE"), binwidth = 5) + # subset for blue data, where aes fill is fill group 1 label
  geom_histogram(data = subset(df, Time_Diff > 12.5), aes(x = Time_Diff, fill="BAR TURQUOISE"), binwidth = 5) + # subset for turquoise data, where aes fill is fill group 2 label
  scale_fill_manual("Histogram Legend", values=c("blue", "paleturquoise2")) + # manually assign histogram fill colors
  geom_vline(aes(xintercept = 3, colour="LINE DARK BLUE"), linetype="twodash", size = 1) + # where aes colour is vline label
  scale_colour_manual("Line Legend", values="darkblue") + #removed legend title
  scale_x_continuous(breaks = seq(0, 202, 10)) +
  ggtitle("Time Difference")  +
  xlab("Time in Days") +
  ylab("Amount") +
  theme_light() +
  theme(panel.grid.minor = element_blank(),
        panel.border = element_blank(), 
        axis.line.x = element_line(size = 0.5, linetype = "solid", colour = "black"), 
        axis.line.y = element_line(size = 0.5, linetype = "solid", colour = "black"),
        legend.position = c(0.95, 0.95),
        legend.justification = c("right", "top"),
        legend.box.just = ("right"))

Answer 1

我认为@Jimbou的建议更可取，但是存在一种变通方法，可以通过将字符值分配给geom_histogram aes fillvalue和geom_vline aes colourvalue，然后在scale_fill_manualor中设置颜色来人为地创建图例scale_colour_manual。

但是，使用这种方法aes fill只会采用一个值（长度1），因此您必须df将蓝色和青绿色值子集化，并为每个值绘制直方图，其截止值由确定binwidth。

这是方法。请注意您的数据需要重新格式化。

# reformat data
set.seed(1)
df <- data.frame(runif(1000, 0, 200))
colnames(df) <- "Time_Diff"


bp_overall <- ggplot(data = df) 
bp_overall +
  geom_histogram(data = subset(df, Time_Diff <= 12.5), aes(x = Time_Diff, fill="BAR BLUE"), binwidth = 5) + # subset for blue data, where aes fill is fill group 1 label
  geom_histogram(data = subset(df, Time_Diff > 12.5), aes(x = Time_Diff, fill="BAR TURQUOISE"), binwidth = 5) + # subset for turquoise data, where aes fill is fill group 2 label
  scale_fill_manual("Histogram Legend", values=c("blue", "paleturquoise2")) + # manually assign histogram fill colors
  geom_vline(aes(xintercept = 3, colour="LINE DARK BLUE"), linetype="twodash", size = 1) + # where aes colour is vline label
  scale_colour_manual("Line Legend", values="darkblue") + # manually assign vline colors
  scale_x_continuous(breaks = seq(0, 202, 10)) +
  ggtitle("Time Difference")  +
  xlab("Time in Days") +
  ylab("Amount") +
  theme_light() +
  theme(panel.grid.minor = element_blank(),
    panel.border = element_blank(), 
    axis.line.x = element_line(size = 0.5, linetype = "solid", colour = "black"), 
    axis.line.y = element_line(size = 0.5, linetype = "solid", colour = "black"))

等添加您剩余的theme。

编辑：回答有关如何统一图例并减小两种图例类型之间的间距的问题

（1）name通过在中设置为“”来删除vline的图例，在中将scale_fill_manual直方图填充图例更改name为“ Legend” scale_colour_manual。

（2）指定order应在其中显示图例的位置，先填充，然后使用着色guides guide_legend。

（3）通过设置legend.spacing.y为来0删除两个图例类型之间的y-spacing ，并使用legend.marginin 删除顶部和底部的边距。theme

bp_overall <- ggplot(data = df) 
bp_overall +
  geom_histogram(data = subset(df, Time_Diff <= 12.5), aes(x = Time_Diff, fill="BAR BLUE"), binwidth = 5) + 
  geom_histogram(data = subset(df, Time_Diff > 12.5), aes(x = Time_Diff, fill="BAR TURQUOISE"), binwidth = 5) + 
  scale_fill_manual(name="Legend", values=c("blue", "paleturquoise2")) +
  geom_vline(aes(xintercept = 3, colour="LINE DARK BLUE"), linetype="twodash", size = 1) + 
  scale_colour_manual(name="", values="darkblue") + 
  scale_x_continuous(breaks = seq(0, 202, 10)) +
  ggtitle("Time Difference")  +
  xlab("Time in Days") +
  ylab("Amount") +
  theme_light() +
  theme(panel.grid.minor = element_blank(),
    panel.border = element_blank(),
    axis.line.x = element_line(size = 0.5, linetype = "solid", colour = "black"),
    axis.line.y = element_line(size = 0.5, linetype = "solid", colour = "black"),
    legend.spacing.y = unit(0, "cm"),
    legend.margin=margin(t=0, r=0.5, b=0, l=0.5, unit="cm")) +
  guides(fill = guide_legend(order = 1), 
     colour = guide_legend(order = 2))