Wrangle cell array of various-sized cell arrays into cell array of cell arrays of size {1xN}

Question

I'm trying to wrangle combnk to generate all the combinations of strings in a cell. E.g.:

someStrings = {'a','b','dog','goat'};
results = arrayfun(@(k) combnk(someStrings,k),1:length(someStrings),'UniformOutput',0);

This gives me a 4*1 cell array of cell arrays with the following dimensions:

{4x1 cell}    {6x2 cell}    {4x3 cell}    {1x4 cell}

What I want is a 15*1 cell array of cell arrays, each of size {1xN}; i.e. 4 cell arrays of size {1,1}, 6 of size {1,2}, etc. How can I do this efficiently?

EDIT: Okay, now I'm here:

results = transpose(arrayfun(@(k) num2cell(combnk(someStrings,k),2),1:length(someStrings),'UniformOutput',0));
finalResults = vertcat(results{:});

Is it possible to turn that into one line? How do you index into a cell array like "{:}", but in the line the cell array was created?

Answer 1

You can achieve it as follows:

intermResults=cellfun(@(x) num2cell(x,2),results,'uni',0);
finalResults=vertcat(intermResults{:});

Explaination: If you look at your results variable, you have those 15 cells. You just need to extract out each row and make it a cell. This is what num2cell(x,2) does. By wrapping it into cellfun, I apply it to each cell in the cell array results. Now you have a 1x4 cell in which each row of results has been converted into a separate cell. You just need to concatenate it to produce the final answer. That's what vertcat(intermResults{:}) does.