r - 创建带有总计行的表格摘要

Question

是否有一个优雅的单线（使用任何 R 包）来完成以下任务？

tab <- aggregate(. ~ Species, dat=iris, mean)
total <- data.frame(Species='Overall', t(colMeans(iris[,-5])))
rbind(tab, total)

Answer 1

包裹tables

library(tables)
tabular( (Species + 1) ~ All(iris)*(mean),data=iris)
> tabular( (Species + 1) ~ All(iris)*(mean),data=iris)

            Sepal.Length Sepal.Width Petal.Length Petal.Width
 Species    mean         mean        mean         mean       
 setosa     5.006        3.428       1.462        0.246      
 versicolor 5.936        2.770       4.260        1.326      
 virginica  6.588        2.974       5.552        2.026      
 All        5.843        3.057       3.758        1.199  

但我作弊并复制了帮助文件中的示例；）感谢 Duncan Murdoch。

或在sqldf

library(sqldf)

库（sqldf）

sqldf(" 
   select Species, 
       avg(Sepal_Length) `Sepal.Length`,
       avg(Sepal_Width) `Sepal.Width`,
       avg(Petal_Length) `Petal.Length`,
       avg(Petal_Width) `Petal.Width` 
    from iris 
    group by Species 
union all 
    select 'All', 
       avg(Sepal_Length) `Sepal.Length`,
       avg(Sepal_Width) `Sepal.Width`, 
       avg(Petal_Length) `Petal.Length`,
       avg(Petal_Width) `Petal.Width` 
    from iris"
)

可以写得更紧凑一点：

variables <- "avg(Sepal_Length) `Sepal.Length`,
    avg(Sepal_Width) `Sepal.Width`,
    avg(Petal_Length) `Petal.Length`,
    avg(Petal_Width) `Petal.Width`"

fn$sqldf(" select Species, $variables from iris group by Species 
    union all select 'All', $variables from iris")

给予

     Species Sepal.Length Sepal.Width Petal.Length Petal.Width
1     setosa     5.006000    3.428000        1.462    0.246000
2 versicolor     5.936000    2.770000        4.260    1.326000
3  virginica     6.588000    2.974000        5.552    2.026000
4        All     5.843333    3.057333        3.758    1.199333

Answer 2

包reshape2在这里可能有点花哨，分为两个步骤：

library(reshape2)
iris.m <- melt(iris, id.vars = "Species")
dcast(Species ~ variable, data = iris.m, fun.aggregate = mean, margins = "Species")
#-----
     Species Sepal.Length Sepal.Width Petal.Length Petal.Width
1     setosa     5.006000    3.428000        1.462    0.246000
2 versicolor     5.936000    2.770000        4.260    1.326000
3  virginica     6.588000    2.974000        5.552    2.026000
4      (all)     5.843333    3.057333        3.758    1.199333

请参阅 ?dcast 上的 margins 参数的详细信息