R allows us to edit (add, delete, or replace) elements of a matrix using the square bracket notation, as depicted in the following lines of code:
mat = matrix(c(1:10),nrow = 2, ncol = 5) mat mat[2,3]
In order to extract any element of a matrix, we can specify the position of that element in R using square brackets. For example, mat[2,3] will extract the element under the second row and the third column. The first numeric value corresponds to the row and the second numeric value corresponds to a column [row, column].
Similarly, to replace an element, we can type the following lines in R:
mat[2,3] = 16
To select all the elements of the second row, we can use mat[2, ]. If we do not specify any numeric value for a column, R will automatically assume all columns.