MATLAB: Replacing a cell array column with another cell array column (conversion to cell from double is not possible)

cellcell arraycellfuncolumn vectordoublereplace

Background:
A is a 1×51 cell – containing 51 Mx6 cells.
Snippet:
B is a 1×51 cell – containing 51 Mx1 doubles.
Snippet:
I want to remove columns 4 and 5 from all 51 cells of A and replace them with the column vectors located in B. So in A{1,1}(:,4:5) is replaced with B{1,1} (B being a cell of column vectors), in A{1,2}{:,4:5} is replaced with B{1,2}.
Since B is doubles and A is cells I can't simply do this:
A{1,1}(:,4) = B{1,1};
A{1,1}(:,5) = [];
Conversion to cell from double is not possible.
>>>>>
Error in IMPORT (line 129)
A{1,1}(:,4)=B{1,1};
So my question is: how do I go about replacing those columns and then how do I loop it through the whole of A to replace each cell's columns? (I'm assuming this can be done using something like cellfun?)
Thanks in advance.

Best Answer

I think the FAQ might help: http://matlab.wikia.com/wiki/FAQ#What_is_a_cell_array.3F
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.
Related Question