在矩阵R中随机放置一个向量

Question

如何将向量a<-c(1,2,3,4,5,6)放置在矩阵m<-matrix(0, nrow = 10, ncol = 10)的ramdom位置？

的载体必须是在一起：

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

而且它必须是水平，垂直或斜 我曾尝试：

start = sample.int(length(m), 1) 
m[start:(start+length(a)-1)] = a 

但它不能发生如下：

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

谢谢

Answer 1

样品相同的尺寸a的一维指数，然后在这些索引分配向量m：

m[sample.int(length(m), length(a))] <- a 
m 
#  [,1] [,2] [,3] [,4] [,5] [,6] [,7] [,8] [,9] [,10] 
# [1,] 0 6 0 0 0 0 0 0 0  0 
# [2,] 0 0 0 0 0 4 0 0 0  0 
# [3,] 0 3 0 1 0 0 0 0 5  0 
# [4,] 0 0 0 0 0 0 0 0 0  0 
# [5,] 0 0 0 0 0 0 0 0 0  0 
# [6,] 0 0 0 0 0 0 0 0 0  0 
# [7,] 0 0 0 0 0 0 0 0 0  0 
# [8,] 0 0 0 0 0 0 0 0 2  0 
# [9,] 0 0 0 0 0 0 0 0 0  0 
#[10,] 0 0 0 0 0 0 0 0 0  0 

---

如果载体必须是连续的，则可以品尝的起始索引，和然后用范围索引分配：

start = sample.int(length(m), 1) 
m[start:(start+length(a)-1)] = a 

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