Эксперимент: Van der Pol radial-stable recurrent cell (#440)

{ "worked": true, "confidence": 8, "verdict": "Built a readable Van der Pol oscillator cell with RK4 integration and reproducible numerical checks. The mechanism manifested: energy injection/removal changed sign exactly at r=R, observed mu-scaling matched the predicted slope (0.0768 versus 0.0768), and all tested initial radii converged to R=1.0 with approximately 6e-10 tail variation. However, the delayed-memory readout did not beat the vanilla tanh reservoir (MSE 0.4474 versus 0.3514), so there was no observed accuracy win; the idea's stated forward-Euler rotation boundary near h omega=2 is also incorrect, while the measured RK4 linear boundary was near h omega=2.8.", "metrics": { "baseline": "Vanilla tanh reservoir: delayed-memory test MSE 0.351394, correlation 0.102633.", "idea": "Van der Pol RK4 cell: delayed-memory test MSE 0.447388, correlation -0.091002; energy-sign means at radii [0.5, 0.8, 1.0, 1.2, 1.5] were [0.09375, 0.1152, approximately 0, -0.3168, -1.40625]; observed and predicted mu slopes were both 0.0768; regulation tail radius was 1.000000001 across initial radii 0.1 to 4.0." }, "how_to_run": "/home/maxwelhelp/main/bin/python3 run_experiment.py && /home/maxwelhelp/main/bin/python3 mini_compare.py", "files": [ "vdp_cell.py", "run_experiment.py", "mini_compare.py", "results.json", "results_stdout.txt" ], "limitations": "Only a small fixed delayed-memory reservoir/readout comparison was tested; no trained Elman/GRU, copy-memory, adding, sequential-MNIST, FLOP-normalized study, learned frequencies, parameter sweeps over R and mu, gradient/Jacobian analysis, or GPU experiment was performed. The Euler stability claim was not confirmed because forward Euler applied to an undamped rotation is expansive for every nonzero step; the reported stability sweep concerns RK4 instead." }