R-gghalves包将图表“合”起来

要想使多个图合理放置，做到既不能互相遮挡又不能更改大小、位置等属性，确实较为麻烦。而R-gghalves包则可以很好的解决这个问题，gghalves包可轻松绘制半面图，如将箱线图分半，这样就可以实现在箱线图旁绘制其他的图表类型。官网为：https://erocoar.github.io/gghalves/。接下来，简单介绍下R-gghalves的主要绘图函数：

  • geom_half_boxplot()：绘制半箱线图
  • geom_half_violin()：绘制半小提琴图
  • geom_half_point()：绘制半点图

由于以上绘图函数和ggplot2中对应的geom_boxplot()、geom_violin()、geom_point()参数类似，这里不再过多赘述。需要注意的是上述三个绘图函数中有一个特殊参数-side用于显示哪一半图形，l代表左，r代表右，默认值为l。

R-gghalves包实例演示

「geom_half_point()」

在使用geom_half_point()函数绘制之前，先使用geom_point()绘制，以便大家更好理解：

  1. point <- ggplot(iris, aes(x = Species, y = Sepal.Width)) + 
  2.   geom_point(shape=21,size=3,fill="#A593E0",colour="black",stroke=.8) +
  3.   labs(
  4.     title = "Example of <span style='color:#D20F26'>gghalves::geom_half_point function</span>",
  5.     subtitle = "processed charts with <span style='color:#1A73E8'>geom_point()</span>",
  6.     caption = "Visualization by <span style='color:#DD6449'>DataCharm</span>") +
  7.   hrbrthemes::theme_ipsum(base_family = "Roboto Condensed") +
  8.   theme(
  9.     plot.title = element_markdown(hjust = 0.5,vjust = .5,color = "black",
  10.                                   size = 20, margin = margin(t = 1, b = 12)),
  11.     plot.subtitle = element_markdown(hjust = 0,vjust = .5,size=15),
  12.     plot.caption = element_markdown(face = 'bold',size = 12))

绘图技巧 | 合理利用图层空间的可视化技巧 - 图1
Example of geom_point()
接下来使用geom_half_point()绘制：

  1. half_point <- ggplot(iris, aes(x = Species, y = Sepal.Width)) + 
  2.   geom_half_point(shape=21,size=3,fill="#A593E0",colour="black",stroke=.8,side = "l")

绘图技巧 | 合理利用图层空间的可视化技巧 - 图2
Example of geom_half_point
可以看出，geom_half_point()使点在水平或者垂直方向上进行抖动，而 side = "l" 的设置则使其左移。
此外，当对不同类别的数据点进行绘制时，则需要使用geom_half_point_panel()，这里和箱线图一同绘制：

  1. ggplot(iris, aes(y = Sepal.Width)) +
  2.   geom_boxplot(fill="#A593E0") +
  3.   geom_half_point_panel(shape=21,size=2.5,colour="black",stroke=.8,
  4.                         aes(x = 0.5, fill = Species),
  5.                         transformation = ggbeeswarm:::position_quasirandom())

绘图技巧 | 合理利用图层空间的可视化技巧 - 图3
Example of geom_half_point_panel and geom_boxplot

「geom_half_boxplot()」

还是一样，首先使用geom_boxplot()绘制：

  1. gplot(iris, aes(x = Species, y = Sepal.Width,fill=Species)) +
  2.   geom_boxplot() +
  3.   ggsci::scale_fill_nejm()+
  4.   labs(
  5.     title = "Example of <span style='color:#D20F26'>gghalves::geom_half_boxplot function</span>",
  6.     subtitle = "processed charts with <span style='color:#1A73E8'>geom_boxplot()</span>",
  7.     caption = "Visualization by <span style='color:#0057FF'>DataCharm</span>") +
  8.   hrbrthemes::theme_ipsum(base_family = "Roboto Condensed") +
  9.   theme(
  10.     plot.title = element_markdown(hjust = 0.5,vjust = .5,color = "black",
  11.                                   size = 20, margin = margin(t = 1, b = 12)),
  12.     plot.subtitle = element_markdown(hjust = 0,vjust = .5,size=15),
  13.     plot.caption = element_markdown(face = 'bold',size = 12))

绘图技巧 | 合理利用图层空间的可视化技巧 - 图4
Example of geom_boxplot
geom_half_boxplot():

  1. ggplot(iris, aes(x = Species, y = Sepal.Width,fill=Species)) +
  2.   geom_half_boxplot(side = "r")

绘图技巧 | 合理利用图层空间的可视化技巧 - 图5
Example of geom_half_boxplot

「geom_half_violin()」

这里直接绘制geom_half_violin()结果：

  1. ggplot(iris, aes(x = Species, y = Sepal.Width,fill=Species)) +
  2.   geom_half_violin(side="r") +
  3.   ggsci::scale_fill_nejm() +
  4.   labs(
  5.     title = "Example of <span style='color:#D20F26'>gghalves::geom_half_violin function</span>",
  6.     subtitle = "processed charts with <span style='color:#1A73E8'>geom_half_violin()</span>",
  7.     caption = "Visualization by <span style='color:#0057FF'>DataCharm</span>") +
  8.   hrbrthemes::theme_ipsum(base_family = "Roboto Condensed") +
  9.   theme(
  10.     plot.title = element_markdown(hjust = 0.5,vjust = .5,color = "black",
  11.                                   size = 20, margin = margin(t = 1, b = 12)),
  12.     plot.subtitle = element_markdown(hjust = 0,vjust = .5,size=15),
  13.     plot.caption = element_markdown(face = 'bold',size = 12))

绘图技巧 | 合理利用图层空间的可视化技巧 - 图6
Example of geom_half_violin()

「geom_half_dotplot()」

  1. ggplot(iris, aes(x = Species, y = Sepal.Width)) +
  2.   geom_half_violin(data = iris,aes(fill=Species)) + 
  3.   geom_dotplot(shape=21,binaxis = "y", method="histodot", stackdir="up",fill="#A593E0",
  4.               colour="black",stroke=1)+
  5.   ggsci::scale_fill_nejm() +
  6.   labs(
  7.     title = "Example of <span style='color:#D20F26'>gghalves::geom_half_violin function</span>",
  8.     subtitle = "processed charts with <span style='color:#1A73E8'>geom_violin()+geom_dotplot</span>",
  9.     caption = "Visualization by <span style='color:#0057FF'>DataCharm</span>") +
  10.   hrbrthemes::theme_ipsum(base_family = "Roboto Condensed") +
  11.   theme(
  12.     plot.title = element_markdown(hjust = 0.5,vjust = .5,color = "black",
  13.                                   size = 20, margin = margin(t = 1, b = 12)),
  14.     plot.subtitle = element_markdown(hjust = 0,vjust = .5,size=15),
  15.     plot.caption = element_markdown(face = 'bold',size = 12))

绘图技巧 | 合理利用图层空间的可视化技巧 - 图7
Example of geom_half_violin_dotplot()
当然，还可以这样：

  1. ggplot(iris, aes(x = Species, y = Sepal.Width,fill=Species)) +
  2.   geom_half_violin() + 
  3.   geom_dotplot(shape=21,binaxis = "y", method="histodot", stackdir="up",
  4.               colour="black",stroke=1) +
  5.   ggsci::scale_fill_jco()

绘图技巧 | 合理利用图层空间的可视化技巧 - 图8
Example02 of geom_half_violin_dotplot()