比如说,我有n个受试者,每个受试者重复t次.如果我想创建一个 Select 矩阵,它将如下所示
n = 5
t = 3
Select_M = diag(n) %x% matrix(1, t)
Select_M
[,1] [,2] [,3] [,4] [,5]
[1,] 1 0 0 0 0
[2,] 1 0 0 0 0
[3,] 1 0 0 0 0
[4,] 0 1 0 0 0
[5,] 0 1 0 0 0
[6,] 0 1 0 0 0
[7,] 0 0 1 0 0
[8,] 0 0 1 0 0
[9,] 0 0 1 0 0
[10,] 0 0 0 1 0
[11,] 0 0 0 1 0
[12,] 0 0 0 1 0
[13,] 0 0 0 0 1
[14,] 0 0 0 0 1
[15,] 0 0 0 0 1
我感兴趣的是每个科目都有不同的时间段.换句话说,第一个主题重复7次,第二个主题重复11次,以此类推.
我如何才能有效地为这些特定重复创建 Select 矩阵?