clc;
clear all;
m = 0.5;    % masa tega
b = 0.2;    % precnik tega
l = 0.7;    % duzina kanapa 
g = 9.81;   % gravitacija
 
r = g/l;   
k = b/(m*l);


figure(1);
f = @(t,x) [x(2); -k*x(2)-r*sin(x(1))];	% f = [??/?t  ;   -b/ml * ??/?t-g/l*sin(?)]
%f = @(t,x) [x(2); -r*sin(x(1))];	% f = [??/?t  ;   -b/ml * ??/?t-g/l*sin(?)]

init = [pi/2; 0];                       % pocetni polozaj  (init = [theta_0 v_0])
[t,x] = ode45(f,[0 300], init);
 
O = [0 0];
axis(gca, 'equal');
axis([-1 1 -1 1]);
grid on;
 
for i = 1: length(t)
   P = l*[sin(x(i,1))  -cos(x(i,1))];
   O_circ = viscircles(O,0.01);
   pend = line([O(1) P(1)], [O(2) P(2)]);
   ball = viscircles(P, 0.05);
   
   pause(0.0001);
   
   if i< length(t)
       delete(pend);
       delete(ball);
       delete(O_circ);
   end
end