How do I solve this looping problem?

Hello all! Please help me solve this. This is a dumbed down problem to what I’m having. I have a time interval of ‘t = 0:ts:N’. For each time step, I need to go through these formulas ‘qt1, F1, FF1, F2 FF2’. Values of FF1 and FF2 are cumulative sums of F1 and F2 respectively. For each time step, I need to do iteration until the condition ‘er’ is met, then I output the result. For each iteration where the condition is not met, I need to take qt1 = FF2 to start calculation of F1, FF1, F2 and FF2 again until the condition is met.

Thanks is advance

tic
clc
clear

w = 20;
p1 = 15;
T1 = 2*pi/w;

ts = T1/25;
N = 0.1;
m = 10;
q0 = 10;
G = 0.05;

n1 = G*p1^2/w;
v1 = n1/p1^2;
pp1 = p1*(1-(v1*p1)^2)^0.5;

t = 0:ts:N;
while 1
   for i = 1:length(t)
      qt1 = q0*sin(w*t(i));
      F1  = ts*qt1.*sin(pp1*t(i)).*exp(n1*t(i))%%(a)
      FF1 = cumsum(F1);% not working
      F2  = ts*qt1.*sin(pp1*t(i+1)).*exp(n1*t(i+1))% (b)%Attempted to access t(9); index out of bounds because numel(t)=8.
      FF2 = cumsum(F2);% not working
      er  = (FF2 - FF1)/FF2
   end
   if er <= 0.05
      break
   else
      qt1 = FF2 % need to take this to calculate F1 and F2, at (a) and (b) above
   end
   FF2   
end
toc

[EDITED, Jan, Code formatted]

[Jan]

The actual problem is hidden in the comment:

 Index exceeds matrix dimensions.
 Error in Untitled (line 27)
      F2  = ts*qt1.*sin(pp1*t(i+1)).*exp(n1*t(i+1))
      index out of bounds because numel(t)=8.

[Deen Halis]

Thanks Jan, so how do i correct this error?

[jgg]

The question is, what should this line do:

 F2  = ts*qt1.*sin(pp1*t(i+1)).*exp(n1*t(i+1))%

When i = length(t)? If you can tell that, you can correct this code. The issue is arising because i iterates up to the end of t then tries to look one step farther, which is impossible.