selecting submatrix of like elements

I need to be able to search a matrix for a submatrix of like elements and then manipulate that group of like elements. For example:

A= [0 0 0 0 0; 0 1 1 0 0; 0 1 1 0 0; 0 0 0 0]

I would like to be able to get at

B= [1 1, 1 1]

and then I would like to randomly move B within A.

The purpose of this is to make a quick demo where I get some tiles to conditionally stick together during a random walk and form larger structures which in turn rotate and move randomly.

Answer 1

[Walter Roberson]

Are the values integers? If so then using the image processing toolbox would possibly be easiest. You can use bwlabel() to find the "islands" in flexible ways, using 4-connection (must be left or right, or up or down) or 8-connection (diagonals allowed) or other custom rules. regionprops() can then give you information about the blobs including lists of coordinates.

[Bahar]

Thank you - this was actually very helpful. I can now find and move the 'islands' in my matrix. Unfortunately, the only way I can move them is 'element by element' which causes them to come apart if they hit some obstruction (as a move isnt legal unless the spot its going to is 0).

You dont happen to know of any way to move like numbers as a unit?