- If the elements within a row of a large matrix (e.g. 10-by-10) follow a sequence, the colon operator
`:`

would be useful. - For example, specifying the elements of a matrix like this,
`[1:10]`

creates a row matrix with 10 elements ascending from 1 to 10. The default increment is 1. In order specify a different incremental value another value is added so that`[4:2:14]`

creates a row matrix with elements 4, 6, 8, 10, 12 and 14 in that order.

- Some examples below show how to create special matrices including an identity matrix and a 0 matrix (with varying dimensions):

**EXERCISE 1**

Try and determine the matrix the codes below would generate. Write them down and then run the code to see if you were right!

`A = eye(7)`

`B = [ 7:12 ]`

`C = [ 0:2:10, 10:4:30]`

`E = [ -pi : pi/4 : pi ]`

(NB: pi = π)`J = ones(2,5)`

**MISCELLANEOUS EXERCISE:**

By hand, try and construct a **3-by-3** matrix using the numbers 1 to 9 in which all the elements in each column and row add up to the same thing. If found that easy, repeat the procedure for a **4-by-4** matrix using 1 to 16.

There’s a way to generate this on MATLAB. (Hint: It is **magic**al.)

(For more on making matrices and special matrices, follow the links: Array Creation and Special Matrices.)