function lorenzdyn(iter,i)
%i=1 3D i=2 2D
clf
hold off
if (i==1)
    t = 0:pi/50:0;
    plot3(sin(t),cos(t),t)
end
hold on
set(gca,'nextplot','replacechildren');
X=zeros(1,iter);
Y=X;
Z=Y;
X=2.9; Y=-1.3; Z=25.9;
XX=2.85; YY=-1.3; ZZ=25.9;
for i=1:iter
    [X1,Y1,Z1]=nextit(X,Y,Z);
    line([X X1],[Y Y1],[Z Z1],'Color',[1 0 0]);
    [X2,Y2,Z2]=nextit(XX,YY,ZZ);
    line([XX X2],[YY Y2],[ZZ Z2]);
    X=X1; Y=Y1; Z=Z1;
    XX=X2; YY=Y2; ZZ=Z2;   
    F(i) = getframe;
end
%movie(F,1);
hold off

function [XO YO ZO]=nextit(X,Y,Z)
    dt=0.02;
    x1=X+10*(Y-X)*dt/2;
	y1=Y+(X*(28-Z)-Y)*dt/2;
	z1=Z+(X*Y-8/3*Z)*dt/2;
	XO=X+10*(y1-x1)*dt;
	YO=Y+(x1*(28-z1)-y1)*dt;
	ZO=Z+(x1*y1-8/3*z1)*dt;