Let's look at what
A{1,1}(:,4) = B{1,1};
actually is. A{1,1} is taking the upper left cell in the 1 by 51 cell array, in other words the first cell since it's a row vector. Since you used braces, you're extracting the cell contents rather than referring to the cell itself. But the cell contents is yet another cell array! It's a cell array of 111 rows of cells by 6 columns of cells. So when you say A{1,1}(:,4), you're taking all the rows in column 4 of that 6 column cell array. So now you have a column vector of cells that is 111 cells tall. Inside each of those 111 cells is a double array, but the expression itself is a column of cells, not doubles , and therein lies the problem.
Now, let's look at B{1,1}. You're using braces so you're extracting the contents of the upper left cell of the B cell array. The contents of that cell is a 111 by 1 column vector of doubles.
Knowing this, and after reading the FAQ, take another crack at it.
