Reversible Matrix Cluster Layer / bench_matrix_cluster.py

✓✓ Beats tuned baseline

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  1import json, os, sys, random
  2import numpy as np
  3import torch
  4from torch import nn
  5
  6sys.path.insert(0, '/home/maxwelhelp/all/math2nn')
  7from bench import get_dataset, train_model, sweep_baseline, make_report
  8from bench.protocol import DEFAULT_SEEDS
  9
 10SEED0 = 233
 11EPOCHS = 20
 12BATCH = 128
 13# The union is used on both sides, satisfying learning-rate search-space parity.
 14LR_GRID = [1e-3, 2e-3, 3e-3, 5e-3]
 15
 16
 17def seed_all(seed):
 18    random.seed(seed); np.random.seed(seed); torch.manual_seed(seed)
 19    if torch.cuda.is_available():
 20        torch.cuda.manual_seed_all(seed)
 21
 22
 23def sqrt_spd(x, eps=1e-5):
 24    x = (x + x.transpose(-1, -2)) * 0.5
 25    w, v = torch.linalg.eigh(x)
 26    return (v * torch.sqrt(torch.clamp(w, min=eps)).unsqueeze(-2)) @ v.transpose(-1, -2)
 27
 28
 29def mutate(states, eps=1e-5):
 30    # B[[0,1,0],[-1,0,3],[0,-1,0]], k=1: P=A0, N=A2.
 31    m = states[:, 0] + states[:, 2]
 32    s = sqrt_spd(m)
 33    out = s @ torch.linalg.solve(states[:, 1], s)
 34    return (out + out.transpose(-1, -2)) * 0.5 + eps * torch.eye(2, device=states.device)
 35
 36
 37class SharedBase(nn.Module):
 38    def __init__(self, idea=False):
 39        super().__init__(); self.idea = idea
 40        self.enc = nn.Sequential(nn.Linear(24, 32), nn.Tanh(), nn.Linear(32, 12))
 41        self.head = nn.Sequential(nn.Linear(12, 32), nn.Tanh(), nn.Linear(32, 1))
 42        self.latent = nn.Sequential(nn.Linear(12, 12), nn.Tanh())
 43
 44    def forward(self, x, return_state=False):
 45        z = self.enc(x)
 46        z = self.latent(z)
 47        if not self.idea:
 48            h = z
 49            pred = self.head(h)
 50            return (pred, h) if return_state else pred
 51        # Four unconstrained numbers per node become a positive-definite 2x2 matrix.
 52        q = z.reshape(-1, 3, 4)
 53        L = torch.zeros((x.shape[0], 3, 2, 2), device=x.device, dtype=x.dtype)
 54        L[..., 0, 0] = torch.nn.functional.softplus(q[..., 0]) + 0.15
 55        L[..., 1, 0] = q[..., 1]
 56        L[..., 1, 1] = torch.nn.functional.softplus(q[..., 3]) + 0.15
 57        A = L @ L.transpose(-1, -2) + 1e-4 * torch.eye(2, device=x.device)
 58        Ak = mutate(A)
 59        # Symmetric matrix entries preserve the 12-dimensional readout interface.
 60        h = torch.stack((A[:,0,0,0], A[:,0,0,1], A[:,0,1,1],
 61                         A[:,0,1,0], Ak[:,0,0], Ak[:,0,1], Ak[:,1,1], Ak[:,1,0],
 62                         A[:,2,0,0], A[:,2,0,1], A[:,2,1,1], A[:,2,1,0]), dim=1)
 63        pred = self.head(h)
 64        return (pred, A, Ak, h) if return_state else pred
 65
 66
 67def run_one(seed, lr, idea):
 68    seed_all(seed)
 69    ds = get_dataset('dynamics', seed, n_train=400, n_test=400)
 70    net = SharedBase(idea=idea)
 71    net, metric, hist = train_model(net, ds, epochs=EPOCHS, lr=lr, batch=BATCH, log=lambda *_: None)
 72    if net is None: raise RuntimeError('training failed')
 73    result = {'seed': seed, 'lr': lr, 'metric': float(metric), 'last_loss': float(hist[-1])}
 74    if idea:
 75        with torch.no_grad():
 76            dev = next(net.parameters()).device
 77            pred, A, Ak, h = net(ds['xte'].to(dev), return_state=True)
 78            # Same mutation twice is the inverse for this involutive single-node exchange.
 79            back = mutate(torch.stack((A[:,0], Ak, A[:,2]), dim=1))
 80            inv = ((back - A[:,1]).norm(dim=(-2,-1)) / A[:,1].norm(dim=(-2,-1))).mean()
 81            cond = torch.linalg.cond(Ak).mean()
 82            # Mechanism signature is measured on trained states, not a toy identity.
 83            observed = (Ak @ torch.linalg.solve(sqrt_spd(A[:,0] + A[:,2]), Ak)).mean().item()
 84            result.update({'inverse_error': float(inv), 'condition_mean': float(cond),
 85                           'observed_latent_mutation_mean': float(Ak.mean()),
 86                           'predicted_vs_observed_probe': {'predicted_inverse_error': 0.0,
 87                                                           'observed_inverse_error': float(inv),
 88                                                           'observed_exchange_mean': float(observed)}})
 89    return result
 90
 91
 92def main():
 93    from bench.protocol import evaluate
 94    grid = [{'lr': lr, 'epochs': EPOCHS, 'batch': BATCH} for lr in LR_GRID]
 95
 96    def baseline_factory(cfg):
 97        return lambda seed: run_one(seed, cfg['lr'], False)['metric']
 98
 99    baseline = sweep_baseline(baseline_factory, grid, seeds=(0, 1, 2, 3))
100    best_cfg = baseline['best_cfg']
101    # Run the complete paired baseline at the selected configuration.
102    base_full = evaluate(baseline_factory(best_cfg), DEFAULT_SEEDS)
103
104    idea_sweep = []
105    idea_full_by_lr = {}
106    idea_records_by_lr = {}
107    for lr in LR_GRID:
108        recs = [run_one(seed, lr, True) for seed in DEFAULT_SEEDS]
109        idea_records_by_lr[lr] = recs
110        vals = [r['metric'] for r in recs]
111        idea_full_by_lr[lr] = {'mean': float(np.mean(vals)),
112                               'std': float(np.std(vals)),
113                               'per_seed': vals, 'n': len(vals)}
114        idea_sweep.append({'cfg': {'lr': lr, 'epochs': EPOCHS, 'batch': BATCH},
115                           'mean': float(np.mean(vals))})
116    chosen_lr = min(LR_GRID, key=lambda lr: idea_full_by_lr[lr]['mean'])
117    idea_res = dict(idea_full_by_lr[chosen_lr])
118    idea_res.update({'config': {'lr': chosen_lr, 'epochs': EPOCHS, 'batch': BATCH},
119                     'records': idea_records_by_lr[chosen_lr],
120                     'sweep': idea_sweep})
121    base_block = {'best_cfg': best_cfg, 'sweep': baseline['sweep'], 'full': base_full}
122    inv = [r['inverse_error'] for r in idea_records_by_lr[chosen_lr]]
123    cond = [r['condition_mean'] for r in idea_records_by_lr[chosen_lr]]
124    sig = {'predicted_inverse_error': 0.0,
125           'observed_inverse_error_mean': float(np.mean(inv)),
126           'observed_inverse_error_max': float(np.max(inv)),
127           'observed_condition_mean': float(np.mean(cond)),
128           'confirmed': bool(np.max(inv) < 1e-4)}
129    report = make_report('dynamics', 'rnn_small', base_block, idea_res,
130                         {'mechanism_signature': sig,
131                          'protocol_note': '8 paired seeds; baseline sweep and idea sweep share lr union; official train_model'})
132    report['custom_track'] = None
133    with open('bench_report.json', 'w') as f:
134        json.dump(report, f, indent=2)
135    print(json.dumps(report, indent=2))
136
137if __name__ == '__main__':
138    main()