1     <span class="keyword">if</span> (strcmp(varargin{na},<span class="string">'alpha'</span>)) <span class="comment">% row vector of length 1, 2 or 3.</span>
0332         alpha = [varargin{na+1} 0 0 0];
0333         alpha = alpha(1:3);
0334         inc = 2;
0335     <span class="keyword">end</span>
0336     <span class="keyword">if</span> (strcmp(varargin{na},<span class="string">'nn'</span>)) <span class="comment">% scalar</span>
0337         alpha(1) = varargin{na+1};
0338         inc = 2;
0339 