我想两个不同的嵌套分组变量的水平出现在图下方单独的行，而不是传说。我现在所拥有的是这样的代码：

data <- read.table(text = "Group Category Value
    S1 A   73
    S2 A   57
    S1 B   7
    S2 B   23
    S1 C   51
    S2 C   87", header = TRUE)

ggplot(data = data, aes(x = Category, y = Value, fill = Group)) + 
  geom_bar(position = 'dodge') +
  geom_text(aes(label = paste(Value, "%")), 
            position = position_dodge(width = 0.9), vjust = -0.25)

我想有是这样的：

有任何想法吗？

Answer 1:

您可以创建自定义元素功能axis.text.x 。

library(ggplot2)
library(grid)

## create some data with asymmetric fill aes to generalize solution 
data <- read.table(text = "Group Category Value
                   S1 A   73
                   S2 A   57
                   S3 A   57
                   S4 A   57
                   S1 B   7
                   S2 B   23
                   S3 B   57
                   S1 C   51
                   S2 C   57
                   S3 C   87", header=TRUE)

# user-level interface 
axis.groups = function(groups) {
  structure(
    list(groups=groups),
    ## inheritance since it should be a element_text
    class = c("element_custom","element_blank")  
  )
}
# returns a gTree with two children: 
# the categories axis
# the groups axis
element_grob.element_custom <- function(element, x,...)  {
  cat <- list(...)[[1]]
  groups <- element$group
  ll <- by(data$Group,data$Category,I)
  tt <- as.numeric(x)
  grbs <- Map(function(z,t){
    labs <- ll[[z]]
    vp = viewport(
             x = unit(t,'native'), 
             height=unit(2,'line'),
             width=unit(diff(tt)[1],'native'),
             xscale=c(0,length(labs)))
    grid.rect(vp=vp)
    textGrob(labs,x= unit(seq_along(labs)-0.5,
                                'native'),
             y=unit(2,'line'),
             vp=vp)
  },cat,tt)
  g.X <- textGrob(cat, x=x)
  gTree(children=gList(do.call(gList,grbs),g.X), cl = "custom_axis")
}

## # gTrees don't know their size 
grobHeight.custom_axis = 
  heightDetails.custom_axis = function(x, ...)
  unit(3, "lines")

## the final plot call
ggplot(data=data, aes(x=Category, y=Value, fill=Group)) + 
  geom_bar(position = position_dodge(width=0.9),stat='identity') +
  geom_text(aes(label=paste(Value, "%")),
            position=position_dodge(width=0.9), vjust=-0.25)+
  theme(axis.text.x = axis.groups(unique(data$Group)),
        legend.position="none")

Answer 2:

该strip.position在参数facet_wrap()和switch参数在facet_grid()因为GGPLOT2 2.2.0使得现在的这个阴谋通过刻面相当简单的简单版本的创建。为了让剧情不间断看，设置panel.spacing为0。

以下是使用不同数量的每个类别组的数据集从@ agtudy的答案的例子。

我用scales = "free_x"从没有它的分类丢弃多余的集团，尽管这并不总是可取的。
该strip.position = "bottom"的说法移动小标签底部。我去掉了带背景一起strip.background ，但我看得出来，留条矩形会在某些情况下非常有用。
我用width = 1 ，使每个类别触控内的酒吧-他们会在默认情况下它们之间有空格。

我也用strip.placement和strip.background的theme ，以获得底部带和删除条矩形。

对于ggplot2_2.2.0或更新版本的代码：

ggplot(data = data, aes(x = Group, y = Value, fill = Group)) + 
    geom_bar(stat = "identity", width = 1) +
    geom_text(aes(label = paste(Value, "%")), vjust = -0.25) +
    facet_wrap(~Category, strip.position = "bottom", scales = "free_x") +
    theme(panel.spacing = unit(0, "lines"), 
         strip.background = element_blank(),
         strip.placement = "outside")

你可以使用space= "free_x"在facet_grid()如果你想所有的酒吧是相同的宽度不管有多少组每个类别的。请注意，这里使用switch = "x"代替strip.position 。您还可能要更改x轴的标签; 我不知道它应该是什么，也许范畴，而不是集团？

ggplot(data = data, aes(x = Group, y = Value, fill = Group)) + 
    geom_bar(stat = "identity", width = 1) +
    geom_text(aes(label = paste(Value, "%")), vjust = -0.25) +
    facet_grid(~Category, switch = "x", scales = "free_x", space = "free_x") +
    theme(panel.spacing = unit(0, "lines"), 
         strip.background = element_blank(),
         strip.placement = "outside") + 
    xlab("Category")

旧的代码版本

对于ggplot2_2.0.0的代码，当首次引入该功能，有点不同。我救了它下面为后人：

ggplot(data = data, aes(x = Group, y = Value, fill = Group)) + 
    geom_bar(stat = "identity") +
    geom_text(aes(label = paste(Value, "%")), vjust = -0.25) +
    facet_wrap(~Category, switch = "x", scales = "free_x") +
    theme(panel.margin = unit(0, "lines"), 
         strip.background = element_blank())

Answer 3:

到agstudy的方法的替代方法是编辑gtable并插入一个“轴线”由GGPLOT2计算

p <- ggplot(data=data, aes(x=Category, y=Value, fill=Group)) + 
  geom_bar(position = position_dodge(width=0.9),stat='identity') +
  geom_text(aes(label=paste(Value, "%")),
            position=position_dodge(width=0.9), vjust=-0.25)

axis <- ggplot(data=data, aes(x=Category, y=Value, colour=Group)) +
  geom_text(aes(label=Group, y=0),
            position=position_dodge(width=0.9))

annotation <- gtable_filter(ggplotGrob(axis), "panel", trim=TRUE)
annotation[["grobs"]][[1]][["children"]][c(1,3)] <- NULL #only keep textGrob

library(gtable)
g <- ggplotGrob(p)
gtable_add_grobs <- gtable_add_grob # let's use this alias
g <- gtable_add_rows(g, unit(1,"line"), pos=4)
g <- gtable_add_grobs(g, annotation, t=5, b=5, l=4, r=4)
grid.newpage()
grid.draw(g)

Answer 4:

一个非常简单的解决方案，它给出了一个类似的（但不相同）的结果是使用小面。不足之处是该类别标签上面，而不是下面。

ggplot(data=data, aes(x=Group, y=Value, fill=Group)) +
  geom_bar(position = 'dodge', stat="identity") +
  geom_text(aes(label=paste(Value, "%")), position=position_dodge(width=0.9), vjust=-0.25) + 
  facet_grid(. ~ Category) + 
  theme(legend.position="none")

Answer 5:

@agstudy已经回答了这个问题，我会用它自己，但如果你愿意接受丑陋的东西，但更简单，这是我带着他的答案之前：

data <- read.table(text = "Group Category Value
    S1 A   73
    S2 A   57
    S1 B   7
    S2 B   23
    S1 C   51
    S2 C   87", header=TRUE)

p <- ggplot(data=data, aes(x=Category, y=Value, fill=Group))
p + geom_bar(position = 'dodge') +
  geom_text(aes(label=paste(Value, "%")), position=position_dodge(width=0.9),   vjust=-0.25) +
  geom_text(colour="darkgray", aes(y=-3, label=Group),  position=position_dodge(width=0.9), col=gray) +
  theme(legend.position = "none", 
    panel.background=element_blank(),
    axis.line = element_line(colour = "black"),
    axis.line.x = element_line(colour = "white"),
    axis.ticks.x = element_blank(),
    panel.grid.major = element_blank(),
    panel.grid.minor = element_blank(),
    panel.border = element_blank(),
    panel.background = element_blank()) +
  annotate("segment", x = 0, xend = Inf, y = 0, yend = 0)

这将给我们：