MATLAB: ERROR: Attempted to access dfi(3); index out of bounds because numel(dfi)=2.

Question

Hello, this is the program I am talking about:

clc;
clear all;
% Vhodni podatki
Lz=0.5; %[m]
k=30; %[N/m]
g=9.81; %[m/s^2]
m=0.2; %[kg]
Tc=100; %[s] Čas celotnega opazovanega intervala
dt=0.001; %[s] Dolžina časovnega intervala od katerega je tudi odvisna napaka pri integriranju po Eulerju
B=0.05; %[N/(m*s)]
% Vodilni enačbi
ar=@(r,dr,fi,dfi) 1/m*(m*r*dfi^2-k*(r-Lz)+m*g*cos(fi)-B*dr);
af=@(r,dr,fi,dfi) 1/(m*r)*(-m*2*dr*dfi-m*g*sin(fi)-B*dfi*r);
% Začetni pogoji
rz=Lz;
drz=0; 
fiz=pi/4; 
dfiz=0; 
% Stanje prve točke
t(1)=0; 
r(1)=rz; 
fi(1)=fiz; 
dr(1)=drz; 
dfi(1)=dfiz; 
Fur(1)=B*dr(1); 
Fuf(1)=B*r*dfi(1); 
nihaj(1)=0; 
ddr(1)=ar(r(1),fi(1),dr(1),dfi(1));
ddfi(1)=af(r(1),fi(1),dr(1),dfi(1));
i=2;
while nihaj<8;  
t(i)=t(i-1)+dt;
r(i)=r(i-1)+dt*dr(i-1);
fi(i)=fi(i-1)+dt*dfi(i-1);
dfi(i)=dfi(i-1)+dt*ddfi(i-1);
dr(i)=dr(i-1)+dt*ddr(i-1);
ddr(i-1)=ar(r(i-1),dr(i-1),fi(i-1),dfi(i-1));
ddfi(i-1)=af(r(i-1),dr(i-1),fi(i-1),dfi(i-1));
i=i+1;
if sign(dfi(i))~=sign(dfi(i-1));
    nihaj=nihaj+1;
end
end 
T=t(end); % Čas 3.5 nihajev

Any1 has a clue where could be the problem? I keep getting the error above…

Regards

Answer 1

Never mind, fixed the problem :)

regards