# While loop doesn't start

1 view (last 30 days)
Nader Mohamed on 29 Oct 2021
Answered: Walter Roberson on 29 Oct 2021
I'm trying to run a while loop until my error reaches the tolerance. But this loop doesn't start. I tried running it without the while loop (putting it manually the parameters) and it workd, but when I want to loop it it doesnt even start, no errors.. My goal here is to find the paramateres b and k that match the minimum error between the sampled solution (y2data) and the numerical solution
toll = 10e-12;
b = 0;
k = 0;
err = 0;
res = [];
while(err>toll)
findbk = @(t,y) [y(3);y(4);k/J1 * y(2) - k/J1 * y(1);T0/J2 - b*y(4)/J2 - (k/J2)*(y(2)-y(1))];
[t,y] = ode45(@(t,y) findbk(t,y),[0:0.01:10],[0,0,0,0]);
fun = @(b,k) T0/J2 - (b/J2).*y(:,4) - ((k/J2).*(y(:,2)-y(:,1)));
err = abs(norm(y2data - fun(b,k)));
res = [res;err];
b = b + 0.01;
k = k + 0.1;
end

Walter Roberson on 29 Oct 2021
0>1e-12 is false.
Initialize error to infinity

R2018b

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