计算 ggplot 中值出现的次数

Question

我有以下数据：

df = data.frame(c("2012","2012","2012","2013"),
                c("tuesday","tuesday","friday","thursday"),
                c("AAA","BBB","AAA","AAA"))
colnames(df) = c("year","day","type")

type我想显示每年和每天值（AAA、BBB）出现的次数（绝对频率） 。目前我编写了以下代码，但它要求我再添加一个维度aes，例如aes(type, some_dimension, fill = as.factor(year))。那么，我怎样才能添加类似的东西count(type)呢？

ggplot(dat) +
  geom_bar(aes(type, fill = as.factor(year)), 
           position = "dodge", stat = "identity") + 
  facet_wrap(~day)

Answer 1

从geom_bar改为stat，如下所示"identity"："count"

library("ggplot2")

ggplot(df) +
    geom_bar(aes(x = type, fill = as.factor(year)), 
             position = "dodge", stat = "count") + 
    facet_wrap(~day)