How to calculate average intensity of the image given in the form of a matrix?

Answer 1

[Walter Roberson]

mean2(TheArray)

[Sandeep saini]

unable to grasp can you please elaborate

[Walter Roberson]

TheArray = [
    1 1 3 2 2
    1 3 1 0 0
    3 3 2 2 0
    1 2 3 0 1
    0 0 1 1 2];
 mean2(TheArray)