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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?
508
The easiest way to remove a row or column from a matrix is to set that row or column equal to a pair of empty square brackets [] . For example, create a 4-by-4 matrix and remove the second row. Now remove the third column.
Right-click in a table cell, row, or column you want to delete. On the menu, click Delete Cells. To delete one cell, choose Shift cells left or Shift cells up. To delete the row, click Delete entire row.
To remove the row(s) and column(s) of a current matrix in R, we use the c() function.
For example, we can use the subset() function if we want to drop a row based on a condition. If we prefer to work with the Tidyverse package, we can use the filter() function to remove (or select) rows based on values in a column (conditionally, that is, and the same as using subset).
You can do:
t1<- t1[-4:-6,-7:-9] If you love us? You can donate to us via Paypal or buy me a coffee so we can maintain and grow! Thank you!
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