  <span class="keyword">end</span>    
0033     m=size(x,2);
0034     tw=size(x,1)*size(x,3);
0035 <span class="keyword">else</span>
0036     <span class="comment">% x and y are cell arrays</span>
0037     n=size(x{1},2)+size(y{1},2);
0038     C=zeros(n,n,length(shifts));
0039     tw=0;
0040     <span class="keyword">for</span> iCell=1:length(x);
0041          <span class="comment">%disp(iCell)</span>
0042          C=C+<a href="nt_cov_lags.html" class="code" title="function [C,tw,m]=nt_cov_lags(x,y,shifts)"