position_stack不适用于facet_wrap

Question

我正在用图表绘制一些份额。我想将标签放在每个分数的中间，但是即使我使用position_stack，它也只能为我提供第一张图（Alberta）所需的标签，而其余部分则没有。

df$label <- scales::percent(df$fuel.share) 
df$label[df$fuel.share < 0.05 ] <- NA

   ggplot(data = df) +
  geom_bar( aes(factor(1),y=fuel.share,fill=Fuel),stat="identity") +
  geom_text(aes(factor(1) ,y=fuel.share, label =label )
            , size =2
            ,position = position_stack(vjust = 0.5)) +
  coord_polar(theta="y") +
  facet_wrap(prov~.) +
  scale_x_discrete(name=" ", breaks = NULL) +
  scale_y_continuous(name=" ", breaks = NULL) 

这是数据集：

 df<- structure(list(Fuel = c("Natural.Gas", "Gasoline", "Diesel", 
 "Light.Fuel.Oil", "Kerosene", "Heavy.Fuel.Oil", "Propane", "Natural.Gas", 
 "Gasoline", "Diesel", "Light.Fuel.Oil", "Kerosene", "Heavy.Fuel.Oil", 
 "Propane", "Natural.Gas", "Gasoline", "Diesel", "Light.Fuel.Oil", 
 "Kerosene", "Heavy.Fuel.Oil", "Propane", "Natural.Gas", "Gasoline", 
 "Diesel", "Light.Fuel.Oil", "Kerosene", "Heavy.Fuel.Oil", "Propane"
), prov = c("Quebec", "Quebec", "Quebec", "Quebec", "Quebec", 
 "Quebec", "Quebec", "Ontario", "Ontario", "Ontario", "Ontario", 
 "Ontario", "Ontario", "Ontario", "Alberta", "Alberta", "Alberta", 
 "Alberta", "Alberta", "Alberta", "Alberta", "Saskatchewan", "Saskatchewan", 
 "Saskatchewan", "Saskatchewan", "Saskatchewan", "Saskatchewan", 
 "Saskatchewan"), year = c(2016, 2016, 2016, 2016, 2016, 2016, 
 2016, 2016, 2016, 2016, 2016, 2016, 2016, 2016, 2016, 2016, 2016, 
 2016, 2016, 2016, 2016, 2016, 2016, 2016, 2016, 2016, 2016, 2016
 ), energy.fuel = c(1.149, 4.68, 15.58, 0.357, 0.105, 0.183, 5.058, 
 22.103, 8.883, 15.142, 1.76, 0.402, 0.019, 4.339, 4.411, 17.441, 
 34.206, 0.015, 0.001, 0, 0.285, 2.624, 16.933, 49.532, 0.026, 
 0.016, 8.718, 0.065), fuel.share = c(0.04237975804072, 0.172617291236353, 
 0.574653290056064, 0.0131676010622603, 0.00387282384184125, 0.00674977869578047, 
 0.186559457066981, 0.419826014283544, 0.168724358000304, 0.287608266220939, 
 0.0334295699741681, 0.00763561768728157, 0.000360887403130223, 
 0.0824152864306336, 0.078266115438528, 0.309462552564808, 0.606930570095282, 
 0.00026615092531805, 1.77433950212034e-05, 0, 0.00505686758104296, 
 0.0336781579690428, 0.217329363143979, 0.635726570321123, 0.000333701260363991, 
 0.000205354621762456, 0.111892599532818, 0.000834253150909978
 ), label = c(NA, "17.3%", "57.5%", NA, NA, NA, "18.7%", "42.0%", 
 "16.9%", "28.8%", NA, NA, NA, "8.2%", "7.8%", "30.9%", "60.7%", 
 NA, NA, NA, NA, NA, "21.7%", "63.6%", NA, NA, "11.2%", NA)), row.names = c(NA, 
 -28L), vars = c("prov", "year"), drop = TRUE, indices = list(
 14:20, 7:13, 0:6, 21:27), group_sizes = c(7L, 7L, 7L, 7L), biggest_group_size = 7L,
 labels = structure(list(
 prov = c("Alberta", "Ontario", "Quebec", "Saskatchewan"), 
 year = c(2016, 2016, 2016, 2016)), class = "data.frame", row.names = c(NA, 
 -4L), vars = c("prov", "year"), drop = TRUE), class = c("grouped_df", 
 "tbl_df", "tbl", "data.frame"))

Answer 1

我认为问题在于geom_text层不太了解要堆叠的内容，尤其是不知道要堆叠的 order 。这是因为Fuel列确定了条形图的堆叠顺序，但在geom_text层上根本没有映射。

最简单的解决方法是将美观贴图移动到ggplot()而不是单个图层中。这样，它将被后续层继承（也避免了在每一层中重复x和y美学）。借助ggplot的魔力，即使geom_text不使用fill映射进行填充，它仍然会知道根据该位置的审美分组/排序。

我已经进行了更改，将文本层的position_stack更改为position_fill，并用geom_bar(stat = "identity")替换了geom_col，这是该成语的首选方法。

ggplot(data = df, aes(factor(1), y = fuel.share, fill = Fuel)) +
  geom_col(position = "fill") +
  geom_text(aes(label = label)
  , size =2
  ,position = position_fill(vjust = 0.5)) +
  coord_polar(theta = "y") +
  facet_wrap(prov ~ .) +
  scale_x_discrete(name = "", breaks = NULL) +
  scale_y_continuous(name = "", breaks = NULL)