Accessing Elements in a Matrix
In R Programming Language we have several methods to Accessing Elements in a Matrix In R we can access matrix elements using square brackets [ ] notation.
Create a matrix
R
# Create a matrixmat <- matrix(1:12,3,4)mat |
Output:
[,1] [,2] [,3] [,4]
[1,] 1 4 7 10
[2,] 2 5 8 11
[3,] 3 6 9 12
Accessing Single Element in a Matrix
R
# Create a matrixmat <- matrix(1:12,3,4)mat# Access the element in the 1st row and 2nd columnelement <- mat[1, 2]print(element) |
Output:
[,1] [,2] [,3] [,4]
[1,] 1 4 7 10
[2,] 2 5 8 11
[3,] 3 6 9 12
[1] 4
Accessing Entire Row or Column
R
# Access the entire 2nd rowrow_vector <- mat[2, ]print(row_vector)# Access the entire 3rd columncol_vector <- mat[, 3]print(col_vector) |
Output:
[1] 2 5 8 11
[1] 7 8 9
Accessing Subsetting Matrix
R
# Create a 3x4 matrixmat <- matrix(1:12,3,4)# Subset a 2x2 matrix from the originalsubset_mat <- mat[1:2, 2:3]print(subset_mat) |
Output:
[,1] [,2]
[1,] 4 7
[2,] 5 8
Accessing matrix Conditional Access
R
# Create a 3x4 matrixmat <- matrix(1:12,3,4)# Access elements greater than 5greater_than_5 <- mat[mat > 5]print(greater_than_5) |
Output:
[1] 6 7 8 9 10 11 12
These methods provide flexibility depending on our specific needs and the structure of our matrices. Choose the one that best fits our use case.
Get element at the specific position from matrix in R
At any point in time, a matrix may be required to be traversed for an element at a specific position. In this article, we are going to access the elements from a matrix in R Programming Language using integer vector, and logical vector as the index.