Creating a Matrix in MATLAB

Defining a matrix in MATLAB is straightforward. Start by naming your matrix, then enclose each row in square brackets. Separate rows with semicolons, and elements within each row with spaces or commas. $$ A=[a_{11}\:\: a_{12}\:\: a_{13}; \\ \:\:\:\:\:\:\:\:\:\: a_{21}\:\: a_{22}\:\: a_{23}; \\ \:\:\:\:\:\:\:\:\:\: a_{31}\:\: a_{32}\:\: a_{33}; ] $$

A practical example

Here’s how to define a 2x3 matrix (2 rows, 3 columns):

$$ M = \begin{pmatrix} 1 & 2 & 3 \\ 4 & 5 & 6 \end{pmatrix} $$

This matrix consists of two rows:

1. The first row includes the elements 1, 2, and 3.
2. The second row includes the elements 4, 5, and 6.

Note: You can separate elements in each row with spaces or commas, but spaces generally improve readability.

To define the matrix, write each row separated by a semicolon:

M = [row1; row2]

In this case:

M = [ 1 2 3 ; 4 5 6 ]

The result is a matrix with two rows and three columns.

Example 2

Now, let’s create a 3x3 square matrix with three rows and three columns:

$$ M = \begin{pmatrix} 1 & 2 & 3 \\ 4 & 5 & 6 \\ 7 & 8 & 9 \end{pmatrix} $$

This matrix consists of three rows:

1. The first row includes the elements 1, 2, and 3.
2. The second row includes the elements 4, 5, and 6.
3. The third row includes the elements 7, 8, and 9.

To define this matrix, write:

M = [ 1 2 3 ; 4 5 6 ; 7 8 9 ]

Separate each element with a space.

You could also use commas instead if you prefer:

M = [ 1, 2, 3 ; 4, 5, 6 ; 7, 8, 9 ]

This will give the same result, though using spaces might make it easier to read.