function mass_plot(scaling, delta, trans, dt, wdir)

if (nargin<1),                    scaling = [];    end
if (nargin<2) | isempty(delta),   delta = .035;    end
if (nargin<3) | isempty(trans),   trans = [.35 0]; end
if (nargin<4) | isempty(dt),      dt = .01;        end

if (nargin<5) | isempty(wdir),
  if isempty(dir('./packet0_r')),
    wdir = [];
  else
    wdir = '.';
  end
end

figure(1); clf; hold on;

for n = 0:50:200,
  drawnow;
  disp(sprintf('plot %d', n));
  pack_circle(packet(n, wdir), scaling, delta, trans);
end

hold off;
