MATLAB: Nested Loop not working

nested loop

The error I am getting is Error using make_nextRow (line 21) Not enough input arguments. but i've rechecked the code and I can't see anything that is wrong
here is the code, and I commented what each line is supposed to to
 function rowfcn = make_nextRow(array, start_row)
  %




  % rowfcn = make_nextRow(array, start_row)
  % 
  % Returns a function handle, rowfcn.  When the function handle
  % is firet called, it will return the row defined by start_row.
  % Every call afterwards will return the next row below.
  %
  % If there are no more rows to return, an empty array, [], is returned.
  %
  % Inputs:
  %   array - A numerical MxN array 
  %   start_row - An index (integer) that indicates 
  %               which row to start returning values from
  %
  % Outputs:
  %   rowfcn - A handle to nextRow, which when alle
  %
M = start_row;
rowfcn = @nextRow; %Return a handle to the NESTED function, nextRow()
end
      function row = nextRow()
          % Check if M is within size(array) and if it is greater than 0
          if M <= array(size) && M > 0
              row = array(M,:);  % Get the M'th row from array and assign to row
              M= M+ 1;             % Increment M
          else
              row = [];
          end
      end
*this is the test case I used: *
scores = [20,90;13,56;3,67;10,78;2,54]
next_score = make_nextRow(scores,1)
next_score()
next_score()
next_score = make_nextRow(scores,4)
next_score()
next_score()
next_score()
these are the answers i'm supposed to get for my test case:
>> scores = [20,90;13,56;3,67; 10,78;2,54]
>>scores=
20 90 13 56 3 67 10 78 2 54
>> next_score = make_nextRow(scores,1)
next_score =
        @make_nextRow/nextRow
>> next_score()
ans = 20 90
>> next_score()
ans = 13 56
>> next_score = make_nextRow(e7_scores,4)
 next_score =
        @make_nextRow/nextRow
>> next_score()
ans = 10 78
>> next_score()
ans = 2 54
>> next_score()
ans = []

Best Answer

Problems with your code:
  • nextRow() is not properly defined as a nested function but rather as a subfunction. As a consequence the input arguments, array and start_row, are "lost".
  • IMO: "M" is not an appropriate name for a row number.
  • "array(size)" should be "size( array, 1 )"
  • "nested loop" in the title is misleading
Your comments and programming style is good
I've modified the code (see below) and run
    scores = [20,90;13,56;3,67;10,78;2,54];
    next_score = make_nextRow( scores, 1 )
    next_score()
    next_score()
which returns
    next_score = 
        @make_nextRow/nextRow
    ans =
        20    90
    ans =
        13    56
    >>
where
    function rowfcn = make_nextRow( array, start_row )
    M = start_row;
    rowfcn = @nextRow; %Return a handle to the NESTED function, nextRow()
        function row = nextRow()
            if M <= size( array, 1 ) && M > 0
                row = array( M, : ); 
                M= M+ 1;             
            else
                row = [];
            end
        end
    end
.
I don't know if that is the expected result. I let you check that.
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