% phase2d  plot phase space for 2 dim discr systems
global x
global RHSNAME;
global flag1;
if (flag1==1), figure; end;
plot(x(:,1),x(:,2));
hold on;
box = axis;

x1 = box(1); x2 = box(2);
y1 = box(3); y2 = box(4);

xlist = [x1 : (x2-x1)/10 : x2];
ylist = [y1 : (y2-y1)/10 : y2];

nx = length(xlist);
ny = length(ylist);

dx = zeros(nx,ny);
dy = zeros(nx,ny);

for ii=1:nx, for jj=1:ny
	xx = [xlist(ii);ylist(jj)];
	yy = feval(RHSNAME,xx);
	dx(ii,jj) = yy(1);
	dy(ii,jj) = yy(2);
end;end;

quiver(xlist,ylist,dx',dy');
axis(box);
%axis('square');
grid;
title('Фазовое пространство дискретной системы');
xlabel('координата x1');
ylabel('координата x2');

hold off;