如何訂購雙向表中的R

Question

我使用下面的命令創建一個表R：

ExamSex<-table(Exam, Sex) 

我想現在排序考試的值的表，並創建一個新表與排序值。我怎樣才能做到這一點？

Answer 1

A table本質上是一個matrix，所以你可以使用它，就像你使用矩陣一樣。

當您在兩個項目上使用table時，rownames成爲第一項的唯一值，而colnames成爲第二項的唯一值。

下面是一個例子：

out <- table(state.division, state.region) 
out 
#      state.region 
# state.division  Northeast South North Central West 
# New England    6  0    0 0 
# Middle Atlantic   3  0    0 0 
# South Atlantic    0  8    0 0 
# East South Central   0  4    0 0 
# West South Central   0  4    0 0 
# East North Central   0  0    5 0 
# West North Central   0  0    7 0 
# Mountain     0  0    0 8 
# Pacific     0  0    0 5 
unique(state.division) 
# [1] East South Central Pacific   Mountain   West South Central 
# [5] New England  South Atlantic  East North Central West North Central 
# [9] Middle Atlantic 
# 9 Levels: New England Middle Atlantic South Atlantic ... Pacific 
unique(state.region) 
# [1] South   West   Northeast  North Central 
# Levels: Northeast South North Central West 

因此，如果我們想在第一個值訂購，我們需要你的表的rownames訂購：

out[order(rownames(out)), ] 
#      state.region 
# state.division  Northeast South North Central West 
# East North Central   0  0    5 0 
# East South Central   0  4    0 0 
# Middle Atlantic   3  0    0 0 
# Mountain     0  0    0 8 
# New England    6  0    0 0 
# Pacific     0  0    0 5 
# South Atlantic    0  8    0 0 
# West North Central   0  0    7 0 
# West South Central   0  4    0 0