Why am I getting a "Not enough input arguments." error in my function?

Not really familiar with MATLAB but I have a couple of sorting functions and would like to compare their running times with the function FindRunningTime:

      function t = FindRunningTime(SortAlg)
          n = 10000.*randn(1,20);

          if strcmp(SortAlg, 'InsertionSort')
              tic;
              InsertionSort(n);
              t = toc;
          else
              tic;
              MergeSort(n);
              t = toc;
          end %if
      end %FindRunningTime

where SortAlg is specified as merge or insert. However when running the code I get the error "Not enough input arguments." on line 2 of both sorting algs. Hopefully someone could point me in the right direction. Also if anyone knows of a nice way to specify the random number generators range, that would be helpful. Below is the code for both sorting algorithms:

function list = MergeSort(list)

      if numel(list) <= 1
          return
      else
          middle = ceil(numel(list) / 2);
          left = list(1:middle);
          right = list(middle+1:end);

          left = sort(left);
          right = sort(right);

          if left(end) <= right(1)
              list = [left right];
              return
          end

          %merge(left,right)
          counter = 1;
          %index placeholder for final list
          while (numel(left) > 0) && (numel(right) > 0)
              if(left(1) <= right(1))
                  list(counter) = left(1);
                  left(1) = [];
              else
                  list(counter) = right(1);
                  right(1) = [];
              end           
              counter = counter + 1;   
          end

          if numel(left) > 0
              list(counter:end) = left;
          elseif numel(right) > 0
              list(counter:end) = right;
          end
          %end merge        
      end %if
  end %MergeSort

function list = InsertionSort(list)

      for i = (2:numel(list))

          value = list(i);
          j = i - 1;

          while (j >= 1) && (list(j) > value)
              list(j+1) = list(j);
              j = j-1;
          end %while

          list(j+1) = value;

      end %for
  end %InsertionSort

[Jan]

The line 2 of MergeSort is empty, so I do not believe that it causes an error. Please post the complete error message also instead of describing it.

What do you mean by "specify the random number generators range"?

[Nicholas Colburn]

Apologies, that would be line 3 of both sorts. Here is the error, it's the same for both; there isn't much to it:

"Error using InsertionSort (line 3) Not enough input arguments."

As far as your second question, I would like to generate a sequence of numbers between 0 and 10,000 using (I'm assuming) some form of the rand() function.

Answer 1

[Walter Roberson]

Hint:

if strcmp(SortAlg, 'InsertionSort')

[Nicholas Colburn]

Thanks for pointing that out! I wasn't quite sure how to compare the two, but unfortunately it still doesn't solve the input argument error.

[Walter Roberson]

Exactly what are you passing as the parameter when you run FindRunningTime ? Show the command line or the line of code.

[Nicholas Colburn]

It would be: FindRunningTime(MergeSort) %or InsertionSort

[Walter Roberson]

FindRunningTime('MergeSort')