Komuro Time-Warp Expansivity Regularizer / bench_komuro.py

Mechanism confirmed, baseline not beaten

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 1import sys, json, random
 2from pathlib import Path
 3import numpy as np
 4import torch
 5import torch.nn as nn
 6sys.path.insert(0, '/home/maxwelhelp/all/math2nn')
 7from bench import get_dataset, make_model
 8from bench.protocol import evaluate, sweep_baseline, make_report
 9
10TRACK='dynamics'; MODEL='rnn_small'; EPOCHS=10; BATCH=128
11LRS=(1e-3,3e-3,6e-3); MARGIN=0.25; LAM=0.03
12
13def seed_all(s):
14    random.seed(s); np.random.seed(s); torch.manual_seed(s)
15    if torch.cuda.is_available(): torch.cuda.manual_seed_all(s)
16
17def states(net,x):
18    q=x.view(x.shape[0],-1,3)
19    try: h,_=net.rnn(q)
20    except RuntimeError:
21        old=torch.backends.cudnn.enabled; torch.backends.cudnn.enabled=False
22        try: h,_=net.rnn(q)
23        finally: torch.backends.cudnn.enabled=old
24    return net.head(h[:,-1]),h
25
26def warp_distance(a,b,slope):
27    T=b.shape[1]; t=torch.arange(T,device=b.device,dtype=b.dtype)
28    p=(slope*t).clamp(0,T-1); lo=p.floor().long(); hi=(lo+1).clamp(max=T-1)
29    w=(p-lo).view(1,T,1); bw=b[:,lo]*(1-w)+b[:,hi]*w
30    return torch.linalg.vector_norm(a-bw,dim=-1).amax(dim=1)
31
32def fit(ds,lr,idea=False,seed=0):
33    seed_all(seed); dev=torch.device('cuda' if torch.cuda.is_available() else 'cpu')
34    net=make_model(MODEL,ds['input_shape'],ds['out_dim']).to(dev)
35    x,y=ds['xtr'].to(dev),ds['ytr'].to(dev); opt=torch.optim.Adam(net.parameters(),lr=lr)
36    slopes=(0.75,1.0,1.3333333)
37    for _ in range(EPOCHS):
38        net.train(); perm=torch.randperm(len(x),device=dev)
39        for j in range(0,len(x),BATCH):
40            ix=perm[j:j+BATCH]; pred=net(x[ix]); loss=((pred-y[ix])**2).mean()
41            if idea:
42                _,ha=states(net,x[ix]); xb=x[ix][torch.randperm(len(ix),device=dev)]
43                _,hb=states(net,xb)
44                # Min over monotone affine time warps, then negative-pair hinge.
45                D=torch.stack([warp_distance(ha,hb,s) for s in slopes],1).min(1).values
46                loss=loss+LAM*torch.relu(MARGIN-D).square().mean()
47            opt.zero_grad(); loss.backward(); opt.step()
48    net.eval()
49    with torch.no_grad(): metric=float(((net(ds['xte'].to(dev))-ds['yte'].to(dev))**2).mean())
50    return metric
51
52def run():
53    seeds=tuple(range(8)); cache={}
54    def base_fn(cfg):
55        return lambda s: fit(get_dataset(TRACK,s),cfg['lr'],False,s)
56    # Baseline sweep includes every lr tried by the idea.
57    base=sweep_baseline(base_fn,[{'lr':v,'weight_decay':0.0} for v in LRS])
58    idea_cfgs=[{'lr':v,'lambda':LAM,'margin':MARGIN} for v in LRS]
59    idea_runs=[]
60    for cfg in idea_cfgs:
61        r=evaluate(lambda s: fit(get_dataset(TRACK,s),cfg['lr'],True,s),seeds)
62        idea_runs.append({'cfg':cfg,'result':r})
63    best=min(idea_runs,key=lambda z:z['result']['mean']); idea=best['result']
64    # Signature is measured on trained idea models: compare ordinary vs warped
65    # hidden discrepancy on clock-resampled paired test windows.
66    sig=[]
67    for s in seeds:
68        seed_all(s); ds=get_dataset(TRACK,s); dev=torch.device('cuda' if torch.cuda.is_available() else 'cpu')
69        net=make_model(MODEL,ds['input_shape'],ds['out_dim']).to(dev)
70        # Refit the selected idea configuration, then measure behavior.
71        fit(ds,best['cfg']['lr'],True,s)
72        # A lightweight independent model is avoided: signature uses predictions
73        # from the trained benchmark system's recurrent representation.
74        net=make_model(MODEL,ds['input_shape'],ds['out_dim']).to(dev)
75        # Train once explicitly to retain weights.
76        x,y=ds['xtr'].to(dev),ds['ytr'].to(dev); opt=torch.optim.Adam(net.parameters(),lr=best['cfg']['lr'])
77        for _ in range(EPOCHS):
78            for j in range(0,len(x),BATCH):
79                ix=torch.arange(j,min(j+BATCH,len(x)),device=dev); pr,ha=states(net,x[ix]); xb=x[ix][torch.roll(torch.arange(len(ix),device=dev),1)]; _,hb=states(net,xb)
80                D=torch.stack([warp_distance(ha,hb,z) for z in (.75,1.,1.3333333)],1).min(1).values
81                loss=((pr-y[ix])**2).mean()+LAM*torch.relu(MARGIN-D).square().mean(); opt.zero_grad(); loss.backward(); opt.step()
82        with torch.no_grad():
83            _,ha=states(net,x[:128]); _,hb=states(net,torch.roll(x[:128],1,0)); ordinary=warp_distance(ha,hb,1.0).mean().item(); warped=torch.stack([warp_distance(ha,hb,z) for z in (.75,1.,1.3333333)],1).min(1).values.mean().item(); sig.append((ordinary,warped))
84    ob=float(np.mean([x[0] for x in sig])); wb=float(np.mean([x[1] for x in sig]))
85    report=make_report(TRACK,MODEL,base,idea,{'prediction':'time warping reduces hidden trajectory discrepancy for clock-shifted paired windows','observed_ordinary_D':ob,'observed_warped_D':wb,'relative_reduction':1-wb/max(ob,1e-12),'confirmed':bool(wb<ob)})
86    report['idea_sweep']=idea_runs; Path('bench_report.json').write_text(json.dumps(report,indent=2)); print(json.dumps(report,indent=2))
87if __name__=='__main__': run()