<span class="comment">% optional input arguments</span>
0042 addParameter(ip, <span class="string">'n_days'</span>, 5, @isnumeric)
0043 
0044 parse(ip, Q, varargin{:})
0045 n_days = ip.Results.n_days;
0046 
0047 <span class="keyword">if</span> floor(n_days)~=n_days &amp;&amp; n_days&lt;1
0048     error(<span class="string">'Filter window must be an integer larger than zero.'</span>)
0049 <span class="keyword">end</span>
0050 
0051 <span class="comment">% Baseflow separation is problematic with NaN values. T