How to delete specific rows and columns from a matrix in a smarter way?
r
Solution
You can do:
t1<- t1[-4:-6,-7:-9]
Problem
Let's say `t1` is : ``` t1 <- array(1:20, dim=c(10,10)) [,1] [,2] [,3] [,4] [,5] [,6] [,7] [,8] [,9] [,10] [1,] 1 11 1 11 1 11 1 11 1 11 [2,] 2 12 2 12 2 12 2 12 2 12 [3,] 3 13 3 13 3 13 3 13 3 13 [4,] 4 14 4 14 4 14 4 14 4 14 [5,] 5 15 5 15 5 15 5 15 5 15 [6,] 6 16 6 16 6 16 6 16 6 16 [7,] 7 17 7 17 7 17 7 17 7 17 [8,] 8 18 8 18 8 18 8 18 8 18 [9,] 9 19 9 19 9 19 9 19 9 19 [10,] 10 20 10 20 10 20 10 20 10 20 ``` I want to delete row 4-6 and column 7-9 from this matrix. I know how to remove it one by one using ``` t2 <- t1[,-7] t3 <- t2[,-8] t4 <- t3[,-9] t5 <- t4[-4,] t6 <- t5[-5,] t7 <- t6[-6,] ``` However, I believe it is the most stupid way of doing it. Could you mind to advice some smarter ways of doing it?