Average Values in a matrix

I have a 100X225 matrix- I want to average [4,4] (or other) chunks of the matrix, and place that value in a new matrix: of a smaller dimension -> 100/4,225/4 etc

I can't seem to get the looping right.

Answer 1

[Azzi Abdelmalek]

a=rand(100,225)
out=blockproc(a,[4 4],@(x) mean(mean(x.data)))