MATLAB: Cellfun with empty cell input

Question

When I use cellfun with an empty cell as input, the output is an empty array. Is that a bug in matlab? How can that be avoided?

If i do x = arrayfun(@(i){y(i)},t),

and t is not an empty array, then x is a cell array and if t is empty, then x is an empty array which i can understand.

but if i do x = cellfun(@(i)y(i),num2cell(t)), i would expect x to be a cell always. no matter what t is.

Is it possible to always have x a cell array without checking if it is empty?

Answer 1

x = cellfun(@fn, c)
x = arrayfun(@fn, a)

x will never be a cell array regardless of input cell array c or array a, unless function fn returns a cell array. Thus with,

x = cellfun(@(i) y(i), num2cell(t))

unless y(i) is a cell array, x will never be a cell array.

To force cellfun and arrayfun to return cell arrays, set 'UniformOutput' to false:

x = cellfun(@(i) y(i), num2cell(t), 'UniformOutput', false)