Index Non-Empty Cells in Cell Array

Hi,

I have the following cell array

TEST = [1] [] [] [] []

I want to get the index position of the non-empty cell. I know I can do this using a loop, but is there any single command (like "find") that will do this?

Thank you!

JF

Answer 1

[Honglei Chen]

x = {1,[],[],[]};
find(~cellfun(@isempty,x))

[John F]

Thanks a lot!

[Jan]

And as usual I mention that "cellfun('isempty', x)" is faster. Although the documentation claims, that this style is kept for backward compatibility only, the string commands are built into the Mex, while the function handle commands require a return to the Matlab interpreter for each cell element.

[Honglei Chen]

Never thought about that but it surely is good to know, thanks Jan.

[Christos Oreinos]

The change in performance is significant for very large cells:

>> x=cell(10000000, 1);
>> x(1980) = {1};
>> tic; find(~cellfun(@isempty, x)); toc
Elapsed time is 5.852150 seconds.
>>
>> tic; find(~cellfun('isempty', x)); toc
Elapsed time is 0.041747 seconds.

[Md. Mubarak Hossain]

a={1 [] [];2 [] 4;5 6 []} find(~cellfun(@isempty,a)) ans =

     1
     2
     3
     6
     8
Here I'm getting answer in column wise. But How to get row wise answer.
That's means I wanna get 
ans=1 4 6 7 8 .
How to get it?

[Serge Kogan]

Md. Mubarak Hossain, You can get it by transposing the cell array a :

a={1 [] [];2 [] 4;5 6 []};

find(~cellfun(@isempty,a'))

Answer 2

[Attila]

Dear Mubarak,

This will work : find(~cellfun(@isempty,a'));