function good = shattersample(X)
% can we shatter the sample X? Should be able to

global NODISPLAY
NODISPLAY = 1;

N = length(X);

G = zeros(N);

for i=1:N
  for j=1:N
    xi = X{i};
    xj = X{j};
    G(i,j) = ptker2(xi,xj);
  end
end

tic
PROGstart(2^N)
for i=2:2^N-1
  Y = zeros(N,1);
  ystr = dec2bin(i-1,N);
  ii1 = find(ystr=='1');
  Y(ii1) = ones(length(ii1),1);
  Y = 2*Y - 1;
  H = G .* (Y*Y');
  
  [nsv, alpha, b0] = svc_gram(H,Y);
  %ii=find(alpha>0);
  %aa=alpha(ii).*Y(ii);

  %y_hat = compute_yhat_gram(H,[1:N],aa,b0);
  y_hat = sign(b0 + H*(Y.*alpha));
  
  good = all(Y==y_hat);
  if ~good
    save PTFAIL X Y
    keyboard
  end
  PROGupdate(i);
  %fprintf('                              %1.9f done; seconds = %1.5f \n',i/2^N,toc);  
end
PROGend;
NODISPLAY = 0;
return


function y_hat = compute_yhat_gram(G,xii,alpha,b)

GX = G(:,xii);

y_hat = sign(b + GX*alpha);

return
nx = length(xii); % for how many x's are we evaluating?
y_hat = zeros(nx,1);
for n=1:nx
  j = xii(n);
  Gj = G(:,j);
  s = b + alpha'*Gj;
  %s = b;
  %for i=1:length(alpha)
  %  s = s + alpha(i) * G(i,j);
  %end
  y_hat(n) = sign(s);
end
return