使用ggplot2和网格

Question

我试图显示几个变量的汇总每周数据的网格图。此图中最相关的两个组成部分是某个变量在给定周内所占的值的分布式汇总图（所以框图或小提琴图）以及累积数周的累积计数图（所以a步骤图）。我想使用grid在对齐的x轴上绘制这两个图。我将使用ggplot2来制作单独的图表，因为我迷上了Hadley Wickham（j / k，ggplot真的非常非常好）。

问题是geom_boxplot只取x轴的因子而geom_step只占x轴的连续数据。即使您使用coord_cartesian或scale_x_...强制使用类似的x限制，这些也不一定会对齐。

我使用geom_rect拼凑了一个可以用于此特定应用程序的黑客攻击，但如果我有一些其他因素导致多个框，那么这将很难适应一个星期。

强制性可重复：

library(ggplot2)
library(grid)

var1 <- data.frame(val = rnorm(300),
                   week = c(rep(25, 100), 
                        rep(26, 100), 
                        rep(27, 100))
                  )

var2 <- data.frame(cumul = cumsum(c(0, rpois(2, 15))),
                   week = c(25, 26, 27)
                  )


g1   <- ggplot(var1, aes(x = factor(week), y = val)) + 
  geom_boxplot()

g2   <- ggplot(var2, aes(x = week, y = cumul)) + 
  geom_step() + scale_x_continuous(breaks = 25:27)

grid.newpage()
grid.draw(rbind(ggplotGrob(g1),
                ggplotGrob(g2),
                size = "last"))

和kludge：

library(dplyr)

chiggity_check <- var1 %>% 
  group_by(week) %>% 
  summarise(week.avg = mean(val),
            week.25  = quantile(val)[2],
            week.75  = quantile(val)[4],
            week.05  = quantile(val)[1],
            week.95  = quantile(val)[5])

riggity_rect <- ggplot(chiggity_check) +
  geom_rect(aes(xmin = week - 0.25, xmax = week + 0.25,
                ymin = week.25,
                ymax = week.75)) +
  geom_segment(aes(x = week - 0.25, xend = week + 0.25,
                   y = week.avg, yend=week.avg),
               color = "white") +
  geom_segment(aes(x = week, xend = week ,
                   y = week.25, yend=week.05)) +
  geom_segment(aes(x = week, xend = week ,
                   y = week.75, yend=week.95)) +
  coord_cartesian(c(24.5,27.5)) +
  scale_x_continuous(breaks = 25:27)

grid.newpage()
grid.draw(rbind(ggplotGrob(riggity_rect),
                ggplotGrob(g2 + coord_cartesian(c(24.5,27.5))),
                size = "last"))

所以问题是：是否有办法强制geom_boxplot到连续轴或geom_step到因子轴？或者是否有其他一些实现，也许stat_summary会更灵活，以便我可以对齐轴并且还可以轻松添加诸如分组颜色变量之类的东西？

Answer 1

一种方法是在设置为factor(week)的x轴上绘制两个图表，但在g2图（步骤图）中在geom_blank()中执行此操作，以便设置比例。然后在geom_step()中，以数字刻度绘制：as.numeric(factor(week))

library(ggplot2)
library(grid)

# Your data
var1 <- data.frame(val = rnorm(300),
                   week = c(rep(25, 100), 
                        rep(26, 100), 
                        rep(27, 100))
                  )

var2 <- data.frame(cumul = cumsum(c(0, rpois(2, 15))),
                   week = c(25, 26, 27)
                  )

# Your g1
g1   <- ggplot(var1, aes(x = factor(week), y = val)) + 
  geom_boxplot()

# Modified g2
g2   <- ggplot(var2) + geom_blank(aes(x = factor(week), y = cumul)) +
geom_step(aes(x = as.numeric(as.factor(week)), y = cumul)) 

grid.newpage()
grid.draw(gridExtra::rbind.gtable(ggplotGrob(g1),
                ggplotGrob(g2),
                size = "last"))