在 prop.table() 中将分类输出相加

Question

新手 - 抱歉。我已经将 prop.table() 应用于数据，我有一个非常基本的问题。我想从分类数据的数据框中自动输出合并的偶尔 AND 经常吸烟者 (0.04 + 0.34 = 0.38)，我该怎么做？

我真的不介意让我了解这里发生了什么的循序渐进的过程。我可以把它应用到其他地方 - 谢谢

编辑：我能想到的唯一过程是尝试移除 not 吸烟者并计算剩余的分类变量，并使用该计数通过基础数学得出比例。但我认为我与这种方法相去甚远

编辑 - 添加 prop.table 代码

OccSmoker <- table(Student1995$smoke)
prop.table(OccSmoker)

$smoke
       Not Occasional    Regular 
      0.62       0.04       0.34

数据帧在这里

> dput(head(Student1995,5))
structure(list(alcohol = structure(c(3L, 2L, 2L, 2L, 3L), .Label = c("Not", 
"Once or Twice a week", "Once a month", "Once a week", "More than once a week"
), class = "factor"), drugs = structure(c(1L, 2L, 1L, 1L, 1L), .Label = c("Not", 
"Tried once", "Occasional", "Regular"), class = "factor"), smoke = structure(c(2L, 
3L, 1L, 1L, 1L), .Label = c("Not", "Occasional", "Regular"), class = "factor"), 
    sport = structure(c(2L, 1L, 1L, 2L, 2L), .Label = c("Not regular", 
    "Regular"), class = "factor")), row.names = c(NA, 5L), class = "data.frame")

汇总数据（如果有帮助）- 编辑

> summary(Student1995)
                  alcohol          drugs           smoke            sport   
 Not                  : 5   Not       :36   Not       :38   Not regular:13  
 Once or Twice a week :16   Tried once: 6   Occasional: 5   Regular    :37  
 Once a month         :12   Occasional: 7   Regular   : 7                   
 Once a week          :14   Regular   : 1                                   
 More than once a week: 3

Answer 1

您可以像这样定义一个新变量 smoke_class，然后将其插入 prop.table()

Student1995$smoke_class <- ifelse(
    Student1995$smoke %in% c("Occasional", "Regular"), # condition
    "Occasional + Regular", # value if condition == TRUE
    Student1995$smoke) # value if condition == FALSE


OccSmoker <- table(Student1995$smoke_class)
prop.table(OccSmoker)

# Not Occasional + Regular 
# 0.6                  0.4

在 prop.table() 中将分类输出相加

Adding categorical outputs together in prop.table()

r

proportions