Create a function in a file named magicfill.m that assigns a magic square to each requested output.

function varargout = magicfill
   nOutputs = nargout;
   varargout = cell(1,nOutputs);

   for k = 1:nOutputs
      varargout{k} = magic(k);
   end

Indexing with curly braces {} updates the contents of a cell.

Call magicfill and request three outputs.

[first,second,third] = magicfill

first =
     1

second =
     1     3
     4     2

third =
     8     1     6
     3     5     7
     4     9     2

MATLAB^® assigns values to the outputs according to their order in the varargout array. For example, first == varargout{1}.

You can use varargout alone in an output argument list, or at the end of the list of outputs, such as

function [x,y,varargout] = myfunction(a,b)

In this case, varargout{1} corresponds to the third output that the function returns, and nargout returns length(varargout) + 2.