.  PhD thesis, Pasadena, CA: Caltech.</span>
0040 
0041 <span class="comment">%   Last Modified By: sbm on Thu Oct  6 20:30:26 2005</span>
0042 
0043 starttime = clock;
0044 
0045 <span class="comment">%%%%%%%%%% DEFAULTS</span>
0046 <span class="keyword">if</span> (nargin &lt; 2),  maxshift = 3;    <span class="keyword">end</span>;   <span class="comment">% default max shift</span>
0047 
0048 <span class="comment">%%%%%%%%%% ARGUMENT CHECKING</span>
0049 <span class="keyword">if</span> (~isfield(spikes, <s