">% if large (say 100), field flows in same direction</span>
<span class="comment">%alphas = [8 4 32];</span>
alphas = [10 10 30 30];
<span class="keyword">for</span> i=1:numel(sigs)
  sig = sigs(i);
  alpha = alphas(i);
  filterwidth = 101;
  [Dx,Dy] = create_distortion_map(I,sig,alpha,filterwidth);
  I2 = distort_image(I,Dx,Dy);

  figure;
  imagesc(I2);colormap(cm)
  set(gca,<span class="string">'XTickLabel'</span>,<span class="string">''</span>)
  set(gca,<span class="string">'YTickLabel'</span>,<span c