r - 按R中的多列排序矩阵

Question

我有一个矩阵

df<-matrix(data=c(3,7,5,0,1,0,0,0,0,8,0,9), ncol=2)
rownames(df)<-c("a","b","c","d","e","f")

[,1] [,2]
a    3    0
b    7    0
c    5    0
d    0    8
e    1    0
f    0    9

我想按降序排列矩阵，首先是第1列，然后是第2列，得出矩阵

df.ordered<-matrix(data=c(7,5,3,1,0,0,0,0,0,0,9,8),ncol=2)
rownames(df.ordered)<-c("b","c","a","e","f","d")

   [,1] [,2]
 b    7    0
 c    5    0
 a    3    0
 e    1    0
 f    0    9
 d    0    8

关于如何实现此目标的任何建议？谢谢。

Answer 1

order函数应该执行此操作。

df[order(df[,1],df[,2],decreasing=TRUE),]