function chain = crf1dtrain (x,y,numClasses)

D = size(x{1},1);
D1 = D+1;
L = size(x{1},2);   % special case - all sequences are of the same length

for i=1:length(x)
  for j=1:L
    x{i}(D1,:) = 1;
  end
end
  
regularizer = 1.0;
clamp = 0;
maxIter = 1000;
chain = crfchain(D1, numClasses, 'clampWeightsForOneState', clamp, 'alpha', regularizer);
chain.w = randn(D1,numClasses);
chain.pot = rand(numClasses,numClasses);

chain = crfchaintrain(chain, x, y, 'gradAlgo', 'scg', 'checkGrad', 'on', 'MaxIter', maxIter, 'verbose', 1);