I am using fminsearch to fit parameters for a system of DEs to observed data. I am not expecting to get a great fit.
fminsearch pretty quickly finds what appears to be an acceptable min for the objective function, but then does not stop. It's running for a really long time, and I cannot figure out why.
I am using the options
options = optimset('Display','iter','TolFun',1e-4,'TolX',1e-4,'MaxFunEvals',1000);
which I understood to mean that when the value of the objective function drops to below 1e-4 that would be considered sufficient. Alternatively when they could no longer change the parameters whatever is the best would be returned.
The output is
Iteration Func-count min f(x) Procedure
0 1 8.13911e+10
1 8 7.2565e+10 initial simplex
2 9 7.2565e+10 reflect
3 10 7.2565e+10 reflect
4 11 7.2565e+10 reflect
5 12 7.2565e+10 reflect
6 13 7.2565e+10 reflect
7 15 6.85149e+10 expand
8 16 6.85149e+10 reflect
9 17 6.85149e+10 reflect
10 19 6.20681e+10 expand
11 20 6.20681e+10 reflect
12 22 5.55199e+10 expand
13 23 5.55199e+10 reflect
14 25 4.86494e+10 expand
15 26 4.86494e+10 reflect
16 27 4.86494e+10 reflect
17 29 3.65616e+10 expand
18 30 3.65616e+10 reflect
19 31 3.65616e+10 reflect
20 33 2.82946e+10 expand
21 34 2.82946e+10 reflect
22 36 2.02985e+10 expand
23 37 2.02985e+10 reflect
24 39 1.20011e+10 expand
25 40 1.20011e+10 reflect
26 41 1.20011e+10 reflect
27 43 5.61651e+09 expand
28 44 5.61651e+09 reflect
29 45 5.61651e+09 reflect
30 47 2.1041e+09 expand
31 48 2.1041e+09 reflect
32 49 2.1041e+09 reflect
33 51 5.15751e+08 expand
34 52 5.15751e+08 reflect
35 53 5.15751e+08 reflect
36 55 7.99868e-05 expand
37 56 7.99868e-05 reflect
38 58 7.99835e-05 reflect
39 59 7.99835e-05 reflect
I have previously let this run for a lot longer and it's stuck with the same min f(x) for at least the next 30 print outs.
How do I set the options correctly so that when it finds a solution within an acceptable value for the objective function it stops?
