How to count three pair of numbers in given matrix?

Hi there,

I have a column matrix:

x = [2 2 1 1 1 1 1 2 1 1 2 2 1 2 1 2 2 1 2 1 2 2 2 1 1 1 2 2 2 2 1 1 2 1 1 2 1 1 1 2 1 1 2 1 1 1 1 2 2 1];

first I want to count a pairs like

1,1,1 = a (say)

1,1,2 = b (say)

1,2,1 = c (say)

1,2,2 = d (say)

2,1,1 = e (say)

2,1,2 = f (say)

2,2,1 = g (say)

2,2,2 = h (say)

I want to create a 4x2 matrix whose elements are as follows:

x_4x2 = [ a b;

c d;

e f;

g h ]

I am not sure how the counting is done.

Your help will be greatly appreciated.

Answer 1

[Rik]

A simple loop should already do the trick.

I can also come up with much more complex solutions. If you split your initial array with cell2mat and convert each element to char, you can use ismember with a lookup table.