Initial commit: ept — backprop-free equilibrium transformer (EP)

Code (ep_run/), organized docs (docs/{method,campaign,hardware,outreach,paper}),
analysis scripts (scripts/), ONBOARDING.md entry point. Large data/checkpoints
git-ignored (share separately).

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_014FAPDWQ49M5Ye3NpTndTpn

1 files changed, 29 insertions, 0 deletions

diff --git a/ep_run/spec_rho_vs_c.py b/ep_run/spec_rho_vs_c.py
new file mode 100644
index 0000000..47661e0
--- /dev/null
+++ b/ep_run/spec_rho_vs_c.py
@@ -0,0 +1,29 @@
+import torch, math, pickle
+from pathlib import Path
+import lt_ep_train as L
+from lt_ep_train import EQBlock
+L.DD=Path('data/tinystories_bpe'); L.vocab=pickle.load(open(L.DD/'meta.pkl','rb'))['vocab_size']
+dev='cuda'; eps=0.1; B=8; T=256; N=800
+torch.manual_seed(1234); idx,y=L.get_batch('val',B,T)
+idx=idx.to(dev) if hasattr(idx,'to') else idx
+def measure_c(ckpt,c):
+    blk=EQBlock(512,16,256,256,s=1.0,c=c,attn_mode='thick'); blk.qknorm=True
+    ck=torch.load(ckpt,map_location=dev)
+    with torch.no_grad():
+        for p,w in zip(blk.allp,ck['allp']): p.copy_(w.to(dev))
+        xin=blk.embed(idx).detach(); z=xin.clone(); ress=[]
+        for t in range(N):
+            z2=z+eps*blk.force(z,xin).detach()
+            r=(z2-z).norm().item()/(z.norm().item()+1e-9); ress.append(r); z=z2
+            if not math.isfinite(r) or r>1e2: break
+    win=[ress[i] for i in range(len(ress)) if 1e-6<ress[i]<1e-1] or ress[-200:]
+    rats=[win[i+1]/win[i] for i in range(len(win)-1) if win[i]>0]
+    rho=math.exp(sum(math.log(x) for x in rats)/len(rats)) if rats else float('nan')
+    return rho, ress[-1]
+print("=== rho vs damping c — does more c pull the operator off the rho=1 threshold? ===")
+print("(weights trained at c=1; this is eval-time c — a margin indicator, not the trained answer)")
+for ck,lab in [('runs/redx_traj/s3200.pt','redx-s3200 (val2.74, marginal)'),('runs/bptt_final.pt','BPTT (1.83)')]:
+    for c in [1.0,1.5,2.0,3.0,4.0]:
+        try: rho,fr=measure_c(ck,c); print(f"  {lab}  c={c}: rho={rho:.4f}  final_res={fr:.2e}")
+        except Exception as e: print(f"  {lab}  c={c}: ERR {repr(e)[:60]}")
+print("=== DONE ===")