R中的什么函数可以使用条件将数据从一个矩阵传输到另一个矩阵?

Question

我有一个超过200列的矩阵，只有2行。我打算把这个矩阵分成4个不同的类别这取决于每一列对应的类别。我该如何使用条件语句呢，还是有其他的方法?例如，我在考虑首先确定每个类别。cat1 <- (matrix.name["第一行名称"，i(每一列的位置])== " A " &matrix.name["第二行名称"，i(每一列的位置])== " B ")我该如何使用cat1来打印一个新的矩阵?

Answer 1

像这样:

some_mtx <- matrix(c(rep('A', 10), rep('C',10), rep('B', 10), rep('D',10)), ncol = 20, byrow=TRUE)
some_mtx
[,1] [,2] [,3] [,4] [,5] [,6] [,7] [,8] [,9] [,10] [,11] [,12] [,13] [,14]
[1,] "A"  "A"  "A"  "A"  "A"  "A"  "A"  "A"  "A"  "A"   "C"   "C"   "C"   "C"  
[2,] "B"  "B"  "B"  "B"  "B"  "B"  "B"  "B"  "B"  "B"   "D"   "D"   "D"   "D"  
[,15] [,16] [,17] [,18] [,19] [,20]
[1,] "C"   "C"   "C"   "C"   "C"   "C"  
[2,] "D"   "D"   "D"   "D"   "D"   "D"  
matrix(c(some_mtx[which(some_mtx =='A')], some_mtx[which(some_mtx == 'D')]), ncol = 10)
[,1] [,2] [,3] [,4] [,5] [,6] [,7] [,8] [,9] [,10]
[1,] "A"  "A"  "A"  "A"  "A"  "D"  "D"  "D"  "D"  "D"  
[2,] "A"  "A"  "A"  "A"  "A"  "D"  "D"  "D"  "D"  "D"  
# or with `byrow=TRUE`
matrix(c(some_mtx[which(some_mtx =='A')], some_mtx[which(some_mtx == 'D')]), ncol = 10, byrow = TRUE)
[,1] [,2] [,3] [,4] [,5] [,6] [,7] [,8] [,9] [,10]
[1,] "A"  "A"  "A"  "A"  "A"  "A"  "A"  "A"  "A"  "A"  
[2,] "D"  "D"  "D"  "D"  "D"  "D"  "D"  "D"  "D"  "D"

想象你的数据对象。