function h = biline (x, y, col)

  newplot ();

  if (nargin < 3)
    col = 'r';
  endif

  tmp = hggroup;

  addproperty ("color", tmp, "color", col);
  addproperty ("marker", tmp, "linemarker", "o");
  addproperty ("barsize", tmp, "double", 0.05);
  
  addlistener (tmp, "color", @update_props);
  addlistener (tmp, "marker", @update_props);
  addlistener (tmp, "barsize", @update_bar);

  m = get (tmp, "barsize");

  x = x(:)';
  y = y(:)';
  xx = [x; x; nan(size(x))];
  xx = xx(:)';
  yy = [y+m; y-m; nan(size(y))];
  yy = yy(:)';

  h1 = line (x, y, "color", col, "parent", tmp);
  h2 = line (xx, yy, "color", col, "linestyle", "-", "marker", "o", "parent", tmp);

  if (nargout > 0)
    h = tmp;
  endif

endfunction

function update_props (h, d)

  kids = get (h, "children");
  set (kids, "color", get (h, "color"));
  set (kids(2), "marker", get (h, "marker"));

endfunction

function update_bar (h, d)

  kids = get (h, "children");
  y = get (kids(1), "ydata");
  m = get (h, "barsize");
  yy = [y+m; y-m; nan(size(y))];
  yy = yy(:)';
  set (kids(2), "ydata", yy);

endfunction