R中有几个变量的频率表

Question

我试图复制官方统计中经常使用的表,但到目前为止没有成功.给定像这样的数据帧:

d1 <- data.frame( StudentID = c("x1", "x10", "x2", 
                          "x3", "x4", "x5", "x6", "x7", "x8", "x9"),
             StudentGender = c('F', 'M', 'F', 'M', 'F', 'M', 'F', 'M', 'M', 'M'),
             ExamenYear    = c('2007','2007','2007','2008','2008','2008','2008','2009','2009','2009'),
             Exam          = c('algebra', 'stats', 'bio', 'algebra', 'algebra', 'stats', 'stats', 'algebra', 'bio', 'bio'),
             participated  = c('no','yes','yes','yes','no','yes','yes','yes','yes','yes'),  
             passed      = c('no','yes','yes','yes','no','yes','yes','yes','no','yes'),
             stringsAsFactors = FALSE)

我想创建一个表格,显示每年,所有学生(所有)和女性,参与者和通过的人数.请注意下面的"ofwhich"指的是所有学生.

我想到的一张桌子看起来像这样:

cbind(All = table(d1$ExamenYear),
  participated      = table(d1$ExamenYear, d1$participated)[,2],
  ofwhichFemale     = table(d1$ExamenYear, d1$StudentGender)[,1],
  ofwhichpassed     = table(d1$ExamenYear, d1$passed)[,2])

我相信在R.这种事情有更好的方法.

注意:我已经看过LaTex解决方案,但我没有使用这对我有用,因为我需要在Excel中导出表.

提前致谢

Answer 1

使用plyr:

require(plyr)
ddply(d1, .(ExamenYear), summarize,
      All=length(ExamenYear),
      participated=sum(participated=="yes"),
      ofwhichFemale=sum(StudentGender=="F"),
      ofWhichPassed=sum(passed=="yes"))

这使:

  ExamenYear All participated ofwhichFemale ofWhichPassed
1       2007   3            2             2             2
2       2008   4            3             2             3
3       2009   3            3             0             2