zadacha.m

function zadacha(x)
% x = L / lambda (например: 5)
  first = true;
  for g = [0:0.1:1,1.05:0.05:1.25]
    if (~first), delete(h1); delete(h2); end
    first = false;
    [h1, h2] = step(x, g);
    pause(0.01);
  end
end

function [h1, h2] = step(x, g)
  % x = L / lambda
  t = 0:pi/360:pi;
  n = length(t);
  r1 = r2 = ones(1, n);
  for i=1:n
    v1 = pi*x*(sin(t(i))+g);
    v2 = pi*x*(sin(t(i))-g);
    if (v1 ~= 0), r1(i) = abs(sin(v1)/v1); end
    if (v2 ~= 0), r2(i) = abs(sin(v2)/v2); end
  end

  h1 = polar(t, r1, 'b');
  hold on;
  h2 = polar(t+pi, r2, 'r');
  grid on;
end