function draw_hist(binVec, gap)
xx = binVec;
plot([0 length(xx)+1],[0 0]);
hold on;
d_xx=[-0.5*gap -.5*gap 0.5*gap 0.5*gap];
for i=1:length(xx),
  d_yy=[0 binVec(i) binVec(i) 0];
  plot(d_xx+i,d_yy);
end;
axis('off');
return;
