The problem is again the tolerance as for the fixed points. I dont know why but it can’t get to 1e-11 in sup norm. You can see that by looking at the newton iterations:
opts_br_po = ContinuationPar(p_min =-100.0, p_max = 400.0, max_steps = 3000, newton_options = NewtonPar(tol = 1e-12, verbose = true), plot_every_step = 150, detect_bifurcation = 0)
br_po2 = @time continuation(br, 3, opts_br_po,
PeriodicOrbitOCollProblem(50,5; jacobian = BK.DenseAnalyticalInplace(), meshadapt = true);
verbosity = 1,
plot = true,
alg = PALC(tangent = Bordered()),
linear_algo = COPBLS(),
normC = norminf,
which gives
Continuation step 310
Step size = 1.0000e-04
Parameter p = 1.4571e+01 ⟶ 1.4571e+01 [guess]
┌─────────────────────────────────────────────────────┐
│ Newton step residual linear iterations │
├─────────────┬──────────────────────┬────────────────┤
│ 0 │ 3.3916e-05 │ 0 │
│ 1 │ 1.2987e-11 │ 1 │
│ 2 │ 2.9181e-12 │ 1 │
│ 3 │ 3.4021e-12 │ 1 │
│ 4 │ 1.1385e-11 │ 1 │
│ 5 │ 7.6389e-12 │ 1 │
│ 6 │ 2.2868e-12 │ 1 │
│ 7 │ 1.7537e-11 │ 1 │
│ 8 │ 1.4163e-11 │ 1 │
│ 9 │ 1.0234e-11 │ 1 │
│ 10 │ 8.0037e-12 │ 1 │
│ 11 │ 1.0922e-11 │ 1 │
│ 12 │ 1.2774e-11 │ 1 │
│ 13 │ 1.9409e-11 │ 1 │
│ 14 │ 1.2409e-11 │ 1 │
│ 15 │ 7.0216e-12 │ 1 │
│ 16 │ 7.3513e-12 │ 1 │
│ 17 │ 1.6162e-11 │ 1 │
│ 18 │ 3.1005e-12 │ 1 │
│ 19 │ 3.1916e-12 │ 1 │
│ 20 │ 9.8766e-12 │ 1 │
│ 21 │ 2.0967e-11 │ 1 │
│ 22 │ 6.6990e-12 │ 1 │
│ 23 │ 2.3850e-12 │ 1 │
│ 24 │ 1.5516e-11 │ 1 │
│ 25 │ 2.2145e-11 │ 1 │
└─────────────┴──────────────────────┴────────────────┘
Instead, if you use smaller tolerances:
br_po2 = @time continuation(br, 3, opts_br_po,
PeriodicOrbitOCollProblem(50,5; jacobian = BK.DenseAnalyticalInplace(), meshadapt = true);
verbosity = 1,
alg = PALC(tangent = Bordered()),
normC = norminf,
callback_newton = BK.cbMaxNorm(1e2), #limit residual to avoid Inf or NaN
)
plot(br, br_po, br_po2)
plot!(br_po2, vars=(:param, :min))
