R：将行索引值添加为rownames

Question

我有这个矩阵：

     [,1] [,2]
 [1,]    0    0
 [2,]    0    0
 [3,]    0    1
 [4,]    1    0
 [5,]    3    2
 [6,]    4    0
 [7,]    0    0
 [8,]    0    0
 [9,]    4    5
[10,]    0    3

我想像这样的数字添加rownames：

   [,1] [,2]
1     0    0
2     0    0
3     0    1
4     1    0
5     3    2
6     4    0
7     0    0
8     0    0
9     4    5
10    0    3

我是手动完成的，但如果我的行数太多，那么我需要花费太长时间。是否有其他更短的方法将行索引添加为rownames？

以下是代码：

mat=matrix(c(0,0,0,1,3,4,0,0,4,0,0,0,1,0,2,0,0,0,5,3), ncol=2)
mat
rownames(mat)=c("1","2","3","4","5","6","7","8","9","10")

Answer 1

对于非常大的矩阵，我可以推荐优化原语：seq_len()。你在这里做

rownames(mat) <- seq_len(nrow(mat))