How to handle unknown output arguments in arrayfun?

Arrayfun can handle to a function that accepts n input arguments and returns m output arguments. But what if we dont know m? If m depends on the input? For example length of the output randperm(n) is n. How to make a matrix nxk in which each column is a different permutation of 1..n?

Answer 1

[Matt J]

You always know "m". It is determined by the number of output arguments you call the function with.

For example length of the output randperm(n) is n. How to make a matrix nxk in which each column is a different permutation of 1..n?

This is a different question. You would do

      n=4;k=3;

   outCell=arrayfun(@(p) randperm(n).', 1:k,'uni',0);

    matrix=[outCell{:}],

but note that for each p=1,...k, the function randperm is being called with just a single output argument. In other words, m is known and is equal to 1.