MATLAB: How to determine which indices in a row cell array contains the value 1, even when there are null vectors [ ] in the cell array

Question

Hello,

If I have a row cell array,

 C = {[], [], [], [], 1, 1, 1, 1, 1, 1, 4, 4, 5, 5, 5, [], [], []}

and I would like to know where in the cell array (i.e. which column) the 1 values are located. How do I grab the indices of where 1 is located because when I use the following,

 d = find([b{:}] == 1)

I get the following output.

 d = [1, 2, 3, 4, 5, 6]

which is not what I want because it ignores the null vector, []…Ideally, I would like the following output, or something like that.

 d = [5, 6, 7, 8, 9, 10]

I'm using MATLAB 2015a btw. Any help or advice would be appreciated. Thanks.

Answer 1

   find(cellfun(@(x) isequal(x,1), C))