MAT2TILES: divide array into equal-sized sub-arrays

MAT2TILES is basically a wrapper for mat2cell but with a more convenient interface when you are simply trying to decompose an N-dimensional array into equal-sized chunks. It takes the desired chunk-size as an input argument, whereas mat2cell does not. MAT2TILES also has some convenient shortcuts for when you only want to tile along particular dimensions (see below).
USAGE:

C=mat2tiles(X,D1,D2,D3,...,Dn)
C=mat2tiles(X,[D1,D2,D3,...,Dn])

will produce a cell array C containing adjacent chunks of the array X, with each chunk of dimensions D1xD2xD3x...xDn. If a dimension Di does not divide evenly into size(X,i), then the chunks at the upper boundary of X along dimension i will be truncated.

It is permissible for the Di to be given value Inf. When this is done, it is equivalent to setting Di=size(X,i). This is useful if you want to tile along only certain array dimensions.

EXAMPLE 1: Split a 28x28 matrix into 4x7 sub-matrices

>> A=rand(28); C=mat2tiles(A,[4,7])

C =

[4x7 double] [4x7 double] [4x7 double] [4x7 double]
[4x7 double] [4x7 double] [4x7 double] [4x7 double]
[4x7 double] [4x7 double] [4x7 double] [4x7 double]
[4x7 double] [4x7 double] [4x7 double] [4x7 double]
[4x7 double] [4x7 double] [4x7 double] [4x7 double]
[4x7 double] [4x7 double] [4x7 double] [4x7 double]
[4x7 double] [4x7 double] [4x7 double] [4x7 double]

EXAMPLE 2: Split a 20x20x6 array into 20x6x3 sub-arrays. This example
illustrates how 'Inf' can be used to indicate that one of the sub-array
dimensions is to be the same as in the original array, in this case size(A,1)=20.


>> A=rand(20,20,6);

>> C=mat2tiles(A,[Inf,6,3]) %equivalent to mat2tiles(A,[20,6,3])

C(:,:,1) =

[20x6x3 double] [20x6x3 double] [20x6x3 double] [20x2x3 double]


C(:,:,2) =

[20x6x3 double] [20x6x3 double] [20x6x3 double] [20x2x3 double]

The example also shows a situation where the original array does not
divide evenly into sub-arrays of the specified size. Note therefore that
some boundary sub-chunks are 20x2x3.