Ok, I have the solution. I can find the rank through this command:
  [A_sorted, rank] = sort(A, 'descend');
  for k=1:10
      rank = find(A_sorted == A(k));
  end
solved Find ranking in matrix in descending order [duplicate]
 
Ok, I have the solution. I can find the rank through this command:
  [A_sorted, rank] = sort(A, 'descend');
  for k=1:10
      rank = find(A_sorted == A(k));
  end
solved Find ranking in matrix in descending order [duplicate]