function yp = ourfunction(t, y)     % A function named ourfunction taking
                                    % two parameters (t, y) and returning one,
                                    % yp.
    yp    = zeros(2, 1);            % To assure that we get a column vector.
    yp(1) = y(1) * (1 - y(2));
    yp(2) = y(2) * (y(1) - 2);
end