- To
**define**a parameter as a matrix, the general procedure involves first stating the name or symbol of the parameter and then stating it is equal to a combination of elements enclosed in square brackets. - For instance, the elements of a 3-by-3 matrix would be typed in like this
`[1,2,3;4,5,6;7,8,9]`

or`[1 2 3; 4 5 6; 7 8 9]`

. The elements within a row are separated by either a**comma or space**; rows are separated by**semicolons**.

**CHECKPOINT**: *Concatenating matrices (*conca* – what?)*

What matrices do you think the following combinations would generate? Try it out by hand first and then run the code!

`C = [A , B]`

`D = [A ; B]`

`E= [A , B; B, A]`

This process is termed **concatenating** of matrices and is used to make larger matrices from smaller ones. Remember, even when we try to compute a matrix by inputting each of the individual components, MATLAB understands them as small 1-by-1 matrices.