 [u1(:),u2(:)]; clear u1; clear u2
  nu = size(u,1);
  covfuncF = {@covFITC, {covfunc}, u};
  inffunc = @infFITC_EP;                       % also @infFITC_Laplace is possible
  hyp = minimize(hyp, @gp, -40, inffunc, meanfunc, covfuncF, likfunc, x, y);
  [a b c d lp] = gp(hyp, inffunc, meanfunc, covfuncF, likfunc, x, y, t, ones(n,1));
</pre>

<p>
We define equispaced inducing points <tt>u</tt> that are shown in the
figure as black circles. Alternatively, a random subset of the training
points can be used as 