How to Assign Row and Column Names in a Matrix in R - Step by Step Examples

How to Assign Row and Column Names in a Matrix in R ?

Answer

To assign row and column names to a matrix in R, you can use the rownames() and colnames() functions. These functions allow you to set or retrieve the row and column names of a matrix.

✐ Examples

1 Assign Row and Column Names to a 2x2 Matrix

In this example,

First, we create a 2x2 matrix named matrix1 using the matrix() function with a vector of values c(1, 2, 3, 4) and specify the number of rows as 2.
Next, we assign row names c('Row1', 'Row2') to the matrix using the rownames() function.
We then assign column names c('Col1', 'Col2') to the matrix using the colnames() function.
Finally, we use the print() function to display the matrix with its row and column names.

R Program

matrix1 <- matrix(c(1, 2, 3, 4), nrow = 2)
rownames(matrix1) <- c('Row1', 'Row2')
colnames(matrix1) <- c('Col1', 'Col2')
print(matrix1)

Output

     Col1 Col2
Row1    1    3
Row2    2    4

2 Assign Row and Column Names to a 3x3 Matrix

In this example,

We first create a 3x3 matrix named matrix2 using the matrix() function with a vector of values c(1, 2, 3, 4, 5, 6, 7, 8, 9) and specify the number of rows as 3.
We assign row names c('A', 'B', 'C') to the matrix using the rownames() function.
We then assign column names c('X', 'Y', 'Z') to the matrix using the colnames() function.
Finally, we use the print() function to display the matrix with its row and column names.

R Program

matrix2 <- matrix(c(1, 2, 3, 4, 5, 6, 7, 8, 9), nrow = 3)
rownames(matrix2) <- c('A', 'B', 'C')
colnames(matrix2) <- c('X', 'Y', 'Z')
print(matrix2)

Output

3 Assign Row and Column Names to a 4x2 Matrix

In this example,

First, we create a 4x2 matrix named matrix3 using the matrix() function with a vector of values c(10, 20, 30, 40, 50, 60, 70, 80) and specify the number of rows as 4.
Next, we assign row names c('R1', 'R2', 'R3', 'R4') to the matrix using the rownames() function.
We then assign column names c('C1', 'C2') to the matrix using the colnames() function.
Finally, we use the print() function to display the matrix with its row and column names.

R Program

matrix3 <- matrix(c(10, 20, 30, 40, 50, 60, 70, 80), nrow = 4)
rownames(matrix3) <- c('R1', 'R2', 'R3', 'R4')
colnames(matrix3) <- c('C1', 'C2')
print(matrix3)

Output

Summary

In this tutorial, we learned How to Assign Row and Column Names in a Matrix in R language with well detailed examples.

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How to Assign Row and Column Names in a Matrix in R - Step by Step Examples

How to Assign Row and Column Names in a Matrix in R ?

Answer

✐ Examples

1 Assign Row and Column Names to a 2x2 Matrix

R Program

Output

2 Assign Row and Column Names to a 3x3 Matrix

R Program

Output

3 Assign Row and Column Names to a 4x2 Matrix

R Program

Output

Summary

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