When I take the pagetranspose of the matrix I, which has the size shown in Fig. 1 below, I get the matrix "Itilde", which has the size shown in Fig. 2.
The pagetranspose function does not change a double array (your original matrix, shown in Fig. 1) into a cell array (Fig. 2). Therefore your code performs some other operation that you're not showing us. If you show us that operation we may be able to help you modify it to achieve your goal.
