function [impres] = grafimp(ar, ma, nqtr, header)
%
nar = length(ar);
nma = length(ma);
eps = zeros(nqtr,1);
t0 = 4;
eps(t0) = 1.0;
y(1:(t0-1)) = zeros(t0-1, 1);
%
for i = t0:nqtr,
   y(i) = eps(i);
   for j = 1:nar,
      y(i) = y(i) + ar(j) * y(i-j);
   end
   for j = 1:nma,
      y(i) = y(i) + ma(j) * eps(i-j);
   end
end
%
t = 0:(nqtr-t0);
plot(t, y(t0:nqtr), 'o'), grid, title(header(1:length(header))),
xlabel('Quarter');
print -dps;
