How do I detect empty cells in a MATLAB cell array?

Question

I have a simple question. How do I detect empty cells in a cell array? I know the command to eliminate the empty cell is a(1) = [], but I can't seem to get MATLAB to automatically detect which cells are empty.

Background: I preallocated a cell array using a=cell(1,53). Then I used if exist(filename(i)) and textscan to check for a file, and read it in. As a result, when the filename(i) does not exist, an empty cell results and we move onto the next file.

When I'm finished reading in all the files, I would like to delete the empty cells of a. I tried if a(i)==[]

Answer 1

Use CELLFUN

%# find empty cells
emptyCells = cellfun(@isempty,a);
%# remove empty cells
a(emptyCells) = [];

Note: a(i)==[] won't work. If you want to know whether the the i-th cell is empty, you have to use curly brackets to access the content of the cell. Also, ==[] evaluates to empty, instead of true/false, so you should use the command isempty instead. In short: a(i)==[] should be rewritten as isempty(a{i}).

Answer 2

The problem should have been treated here already, you can try this approach:

http://stackoverflow.com/questions/2624016/replace-empty-cells-with-logical-0s-before-cell2mat-in-matlab