function [AA1,C] = smartcollapse(AA,C)
N = size(AA,1);
T = size(AA,3);
for t=1:T
  [h0,i0,j0] = SC(AA(:,:,t));
  merge = setdiff(1:N,i0);
  tha = pnormdim(rand(N-1,1),1);
  AA1(:,:,t) = collapse(AA(:,:,t),merge,tha);
end
return


function [h,i0,j0] = SC(AA)
% the "stricture coefficient" of AA
[n,n,T] = size(AA);
h = 0;
for t=1:T
  A = AA(:,:,t);
  for i=1:n
    for j=i+1:n
      x = A(:,i);
      y = A(:,j);
      hxy = max(abs(x-y));
      if (hxy>h)
        i0=i;j0=j;h=hxy;
      end
    end
  end
end
return