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giant/tests/test_train.py
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Add per-stage init_from/freeze (gitea #42)
stage{1,2}_model.active = false already trains one stage alone, but the
checkpoint it writes holds only that stage, so giant rollout refuses it --
the "retrain stage 2 alone against a fixed, known-good stage 1" experiment
the 2026-08-03 species failure calls for wasn't runnable end to end.

Adds stage{1,2}_model.init_from (a checkpoint .pt to load this stage's
weights from before training) and .freeze (never update them), symmetric
across both stages. Both stages stay active = true, so both get built and
both land in the output checkpoint -- the frozen stage is merely
initialized from disk instead of from scratch.

Decisions made during planning:
- Soft freeze: forward/backward still run every batch (loss/grad_norm stay
  meaningful, no autograd special-casing), only optimizer.step() (and, for
  the frozen stage, lr_sched.step()/EMA update) is skipped -- weights are
  byte-identical for the whole run. This is StageTrainer._step_optimizer,
  shared by the non-adversarial path and both halves (generator + critic)
  of the WGAN path, so a frozen WGAN stage's critic freezes too.
- validate_config requires init_from whenever freeze = true, unless the run
  is a --resume (a resumed frozen stage's weights come from the resume
  checkpoint instead) -- freezing a randomly-initialized model is almost
  certainly a mistake.
- CLI flags on both `giant train` and `giant new-run`
  (--stage{1,2}-init-from/--stage{1,2}-freeze), matching every other
  per-stage model knob's existing treatment.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
2026-08-17 14:23:20 +02:00

1126 lines
44 KiB
Python

"""Tests for giant/training/."""
import copy
import csv
import math
import tempfile
from pathlib import Path
from unittest.mock import MagicMock, patch
import numpy as np
import pytest
import torch
from giant.config import ParticleTypeConfig
from giant.constants import (
COND_DIM,
CONT_SLOT_DIM,
K_MAX,
PARTICLE_PHYS_DIM,
SEC_SLOT_DIM,
X_DIM,
)
from giant.checkpoint_io import load_for_inference
from giant.data.dataset import StepBatch
from giant.data.transforms import Normalizer
from giant.model.network import Stage2Autoregressive, build_critics, build_models
from giant.sample import sample_stage1 as trainers_sample_stage1
from giant.training import (
FlowDDPMStageTrainer,
StageSpec,
WGANStageTrainer,
build_checkpoint,
build_stage_trainers,
init_stages_from_checkpoints,
train,
)
from giant.training.metrics import _wandb_run_config
from giant.training.stage2_inputs import (
_ar_has_prev,
_assemble_stage2_ar_inputs,
_assemble_stage2_ar_target,
_assemble_stage2_real,
_gumbel_tau,
_relax_onehot_type_slice,
_remaining_energy_fraction,
_shift_prev,
_stage2_tf_prob,
_stick_fraction,
_stop_target_and_mask,
_type_repr,
)
PDG_VOCAB = 6
MAT_VOCAB = 3
def test_gumbel_tau_at_step_zero_is_start():
assert _gumbel_tau(0, 1000, 1.0, 0.1) == 1.0
def test_gumbel_tau_at_total_steps_is_end():
assert abs(_gumbel_tau(1000, 1000, 1.0, 0.1) - 0.1) < 1e-9
def test_gumbel_tau_interpolates_linearly_midway():
assert abs(_gumbel_tau(500, 1000, 1.0, 0.1) - 0.55) < 1e-9
def test_gumbel_tau_clamps_beyond_total_steps():
assert _gumbel_tau(5000, 1000, 1.0, 0.1) == _gumbel_tau(1000, 1000, 1.0, 0.1)
def test_gumbel_tau_handles_zero_total_steps():
# total_steps=0 is guarded to 1 internally: step=0 gives zero progress
# (still tau_start), any step>=1 immediately clamps to full progress.
assert _gumbel_tau(0, 0, 1.0, 0.1) == 1.0
assert abs(_gumbel_tau(1, 0, 1.0, 0.1) - 0.1) < 1e-9
def test_wandb_run_config_includes_full_cfg_and_param_counts():
cfg = {
"train": {"lr": 3e-4},
"conditioning": {"out_dim": 128},
"stage1_model": {"generator": "flow"},
"stage2_model": {"generator": "wgan"},
}
wcfg = _wandb_run_config(cfg, model_config={"pdg_vocab": 3}, param_counts={"stage1": 100})
assert wcfg["train"] == {"lr": 3e-4}
assert wcfg["stage1_model"] == {"generator": "flow"}
assert wcfg["stage2_model"] == {"generator": "wgan"}
assert wcfg["model_config"] == {"pdg_vocab": 3}
assert wcfg["param_counts"] == {"stage1": 100}
def test_wandb_run_config_handles_missing_model_config():
cfg = {"train": {}, "conditioning": {}, "stage1_model": {}, "stage2_model": {}}
wcfg = _wandb_run_config(cfg, model_config=None, param_counts={})
assert wcfg["model_config"] == {}
# --- AR helper functions (v0.3.0 step 5) ---------
def test_stick_fraction_matches_sigmoid_of_logit():
sec_cont = torch.zeros(2, 3, SEC_SLOT_DIM)
sec_cont[..., 0] = torch.tensor([[0.0, 2.0, -2.0], [1.0, -1.0, 0.0]])
frac = _stick_fraction(sec_cont)
assert torch.allclose(frac, torch.sigmoid(sec_cont[..., 0]))
def test_remaining_energy_fraction_hand_computed():
fraction = torch.tensor([[0.5, 0.5, 1.0]])
remaining = _remaining_energy_fraction(fraction)
assert torch.allclose(remaining, torch.tensor([[1.0, 0.5, 0.25]]))
def test_shift_prev_shifts_and_zero_pads_slot0():
x = torch.arange(2 * 4 * 3).reshape(2, 4, 3).float()
shifted = _shift_prev(x)
assert torch.all(shifted[:, 0] == 0)
assert torch.equal(shifted[:, 1:], x[:, :-1])
def test_ar_has_prev_false_only_at_slot_zero():
has_prev = _ar_has_prev(5, torch.device("cpu"))
assert has_prev.shape == (1, 5)
assert has_prev.tolist() == [[False, True, True, True, True]]
def test_stop_target_and_mask_hand_computed():
# k_max=5; n_sec=0 (no real secondaries, stop slot is 0), n_sec=2
# (stop slot is 2), n_sec=5 (== k_max: no in-range stop slot at all).
n_sec = torch.tensor([0, 2, 5])
target, mask = _stop_target_and_mask(n_sec, 5, torch.device("cpu"))
assert target.tolist() == [
[1, 0, 0, 0, 0],
[0, 0, 1, 0, 0],
[0, 0, 0, 0, 0],
]
assert mask.tolist() == [
[True, False, False, False, False],
[True, True, True, False, False],
[True, True, True, True, True],
]
# --- _stage2_tf_prob (v0.3.0 step 7) -----------
def test_stage2_tf_prob_always_is_constant_one():
assert _stage2_tf_prob("always", 1.0, 0.0, 0, 10) == 1.0
assert _stage2_tf_prob("always", 1.0, 0.0, 9, 10) == 1.0
def test_stage2_tf_prob_never_is_constant_zero():
assert _stage2_tf_prob("never", 1.0, 1.0, 0, 10) == 0.0
assert _stage2_tf_prob("never", 1.0, 1.0, 9, 10) == 0.0
def test_stage2_tf_prob_scheduled_interpolates_linearly():
assert _stage2_tf_prob("scheduled", 1.0, 0.0, 0, 11) == 1.0
assert abs(_stage2_tf_prob("scheduled", 1.0, 0.0, 5, 11) - 0.5) < 1e-9
assert _stage2_tf_prob("scheduled", 1.0, 0.0, 10, 11) == 0.0
def test_stage2_tf_prob_scheduled_clamps_beyond_total_epochs():
end = _stage2_tf_prob("scheduled", 1.0, 0.0, 10, 11)
beyond = _stage2_tf_prob("scheduled", 1.0, 0.0, 50, 11)
assert beyond == end
def test_stage2_tf_prob_scheduled_handles_single_epoch():
# total_epochs=1 is guarded to a denominator of 1 internally (like
# _gumbel_tau's total_steps=0 guard) — epoch=0 gives zero progress.
assert _stage2_tf_prob("scheduled", 1.0, 0.0, 0, 1) == 1.0
@pytest.mark.parametrize("target", ["physical", "onehot", "embedding"])
def test_type_repr_shapes_and_values(target):
B, K, emb_dim = 3, 4, 6
sec_cont = torch.randn(B, K, SEC_SLOT_DIM)
sec_type_idx = torch.randint(0, emb_dim, (B, K))
cond_enc = torch.nn.Module()
if target == "embedding":
cond_enc.pdg_emb = torch.nn.Embedding(emb_dim, emb_dim)
repr_ = _type_repr(sec_type_idx, sec_cont, ParticleTypeConfig(target=target), cond_enc, emb_dim)
expected_width = PARTICLE_PHYS_DIM if target == "physical" else emb_dim
assert repr_.shape == (B, K, expected_width)
if target == "physical":
assert torch.equal(repr_, sec_cont[..., CONT_SLOT_DIM : CONT_SLOT_DIM + PARTICLE_PHYS_DIM])
if target == "onehot":
assert torch.all(repr_.sum(-1) == 1.0)
@pytest.mark.parametrize(
"target,generator",
[
("physical", "flow"),
("physical", "wgan"),
("onehot", "flow"),
("onehot", "wgan"),
("embedding", "flow"),
("embedding", "wgan"),
],
)
def test_assemble_stage2_ar_target_matches_assemble_stage2_real_flattened(target, generator):
"""Regression test tying the refactor together: _assemble_stage2_real is
now defined as _assemble_stage2_ar_target(...).flatten(1)."""
B, emb_dim = 4, 6
sec_cont = torch.randn(B, K_MAX, SEC_SLOT_DIM)
sec_type_idx = torch.randint(0, emb_dim, (B, K_MAX))
cond_enc = torch.nn.Module()
if target == "embedding":
cond_enc.pdg_emb = torch.nn.Embedding(emb_dim, emb_dim)
particle_type_cfg = ParticleTypeConfig(target=target)
flat = _assemble_stage2_real(sec_cont, sec_type_idx, particle_type_cfg, generator, cond_enc, emb_dim)
unflat = _assemble_stage2_ar_target(sec_cont, sec_type_idx, particle_type_cfg, generator, cond_enc, emb_dim)
assert torch.equal(unflat.flatten(1), flat)
def test_assemble_stage2_ar_inputs_shapes_and_history_feat_width():
B, emb_dim = 3, 6
sec_cont = torch.randn(B, K_MAX, SEC_SLOT_DIM)
sec_type_idx = torch.randint(0, emb_dim, (B, K_MAX))
cond_enc = torch.nn.Module()
out = _assemble_stage2_ar_inputs(sec_cont, sec_type_idx, ParticleTypeConfig(target="physical"), cond_enc, emb_dim)
assert out["history_feat"].shape == (B, K_MAX, CONT_SLOT_DIM + PARTICLE_PHYS_DIM)
assert out["has_prev"].shape == (B, K_MAX)
assert out["remaining_frac"].shape == (B, K_MAX)
assert out["slot_idx"].shape == (B, K_MAX)
assert torch.all(out["slot_idx"][:, 0] == 0.0)
assert torch.all(out["slot_idx"][:, -1] == 1.0)
def test_relax_onehot_type_slice_grad_probe_populates_both_norms():
B, k_max, cont_dim, type_dim = 4, K_MAX, CONT_SLOT_DIM, 6
x_flat = torch.randn(B, k_max * (cont_dim + type_dim), requires_grad=True)
grad_probe: dict[str, float] = {}
out = _relax_onehot_type_slice(x_flat, k_max, cont_dim, type_dim, tau=0.5, grad_probe=grad_probe)
out.sum().backward()
assert grad_probe["cont"] >= 0.0
assert grad_probe["type"] >= 0.0
def test_relax_onehot_type_slice_grad_probe_none_is_backward_compatible():
B, k_max, cont_dim, type_dim = 4, K_MAX, CONT_SLOT_DIM, 6
x_flat = torch.randn(B, k_max * (cont_dim + type_dim), requires_grad=True)
out = _relax_onehot_type_slice(x_flat, k_max, cont_dim, type_dim, tau=0.5)
out.sum().backward()
assert x_flat.grad is not None
# --- end-to-end train() integration tests -----------------------------------
PARTICLE_CFG = {"type": "physical", "emb_dim": 8, "n_layers": 1}
MATERIAL_CFG = {"type": "physical", "emb_dim": 8, "n_layers": 1}
def _base_cfg():
return {
"conditioning": {
"out_dim": 32,
"share_stages": False,
"particle": dict(PARTICLE_CFG),
"material": dict(MATERIAL_CFG),
},
"stage1_model": {
"active": True,
"generator": "flow",
"hidden_dim": 24,
"n_res_blocks": 2,
"dropout": 0.0,
"lambda": 1.0,
"flow": {"time_dim": 16},
"ddpm": {"time_dim": 16, "n_steps": 50},
"wgan": {
"noise_dim": 16,
"n_critic": 2,
"gp_weight": 10.0,
"critic_lr": 0.0,
},
"router": {"enabled": False},
},
"stage2_model": {
"active": True,
"decoder": "one_shot",
"generator": "wgan",
"hidden_dim": 24,
"n_res_blocks": 2,
"dropout": 0.0,
"lambda": 1.0,
"k_max": K_MAX,
"context_dim": 16,
"n_sec": {"mode": "head", "lambda": 0.1},
# Explicit, not relying on the fallback default (which is
# "onehot", matching DEFAULT_CONFIG — see issues.md Issue 1):
# the "physical"-labelled cases below (and this fixture's own
# comment history) intend this as the base "physical" case,
# with "*_onehot"/"*_embedding" cases opting in explicitly.
"particle_type": {"target": "physical", "lambda": 1.0},
"flow": {"time_dim": 16},
"ddpm": {"time_dim": 16, "n_steps": 50},
"wgan": {
"noise_dim": 16,
"n_critic": 2,
"gp_weight": 10.0,
"critic_lr": 0.0,
},
"router": {"enabled": False, "tie_to_stage1": False},
},
"train": {
"epochs": 2,
"batch_size": 8,
"lr": 3e-4,
"weight_decay": 0.01,
"ema_decay": 0.999,
"warmup_epochs": 0,
"val_fraction": 0.1,
"max_val_batches": 0,
"num_workers": 0,
"seed": 0,
"validate_every": 0,
"validate_steps": 2,
"wandb": False,
},
}
def _fake_batches(n_batches, batch_size, seed=0):
g = torch.Generator().manual_seed(seed)
batches = []
for _ in range(n_batches):
cond_cont = torch.randn(batch_size, COND_DIM, generator=g)
cond_cat = torch.stack(
[
torch.randint(0, PDG_VOCAB, (batch_size,), generator=g),
torch.randint(0, MAT_VOCAB, (batch_size,), generator=g),
],
dim=1,
)
x1 = torch.randn(batch_size, X_DIM, generator=g)
n_sec = torch.randint(0, K_MAX, (batch_size,), generator=g)
sec_cont = torch.randn(batch_size, K_MAX, SEC_SLOT_DIM, generator=g)
proc_idx = torch.zeros(batch_size, dtype=torch.long)
sec_type_idx = torch.zeros(batch_size, K_MAX, dtype=torch.long)
batches.append(StepBatch(cond_cont, cond_cat, x1, n_sec, sec_cont, proc_idx, sec_type_idx))
return batches
def _model_config(cfg):
return {
"pdg_vocab": PDG_VOCAB,
"mat_vocab": MAT_VOCAB,
"conditioning": cfg["conditioning"],
"stage1_model": cfg["stage1_model"],
"stage2_model": cfg["stage2_model"],
}
def _run_train(cfg, out_dir, resume_path=None, normalizer_dict=None):
model_config = _model_config(cfg)
models = build_models(model_config)
critics = build_critics(model_config)
train_loader = _fake_batches(4, cfg["train"]["batch_size"])
val_loader = _fake_batches(2, cfg["train"]["batch_size"], seed=1)
train(
cfg=cfg,
models=models,
critics=critics,
train_loader=train_loader,
val_loader=val_loader,
device=torch.device("cpu"),
out_dir=out_dir,
normalizer_dict=normalizer_dict or {"cond": {}, "target": {}, "sec_phys": {}},
pdg_map={"22": 0},
mat_map={"G4_AIR": 0},
proc_map=None,
model_config=model_config,
total_train_batches=4,
resume_path=resume_path,
)
@pytest.mark.parametrize(
"label,mutate",
[
("both_flow", lambda cfg: None),
("both_wgan", lambda cfg: cfg["stage1_model"].__setitem__("generator", "wgan")),
(
"mixed_stage1_flow_stage2_wgan",
lambda cfg: None, # already the default
),
(
"mixed_stage1_wgan_stage2_flow",
lambda cfg: (
cfg["stage1_model"].__setitem__("generator", "wgan"),
cfg["stage2_model"].__setitem__("generator", "flow"),
),
),
("stage1_only", lambda cfg: cfg["stage2_model"].__setitem__("active", False)),
("stage2_only", lambda cfg: cfg["stage1_model"].__setitem__("active", False)),
(
"both_ddpm_stage1_flow_stage2",
lambda cfg: (
cfg["stage1_model"].__setitem__("generator", "ddpm"),
cfg["stage2_model"].__setitem__("generator", "flow"),
),
),
(
"routed_stage1_energy_gumbel",
lambda cfg: cfg["stage1_model"].__setitem__(
"router",
{
"enabled": True,
"type": "energy",
"n_experts": 3,
"temperature": 0.5,
"learn_centers": True,
"lambda_balance": 0.1,
"lambda_entropy": 0.01,
"gumbel": True,
"gumbel_tau_start": 1.0,
"gumbel_tau_end": 0.1,
},
),
),
(
"stage2_onehot_target_wgan",
lambda cfg: cfg["stage2_model"].__setitem__("particle_type", {"target": "onehot", "lambda": 1.0}),
),
(
"stage2_onehot_target_flow",
lambda cfg: (
cfg["stage2_model"].__setitem__("generator", "flow"),
cfg["stage2_model"].__setitem__("particle_type", {"target": "onehot", "lambda": 1.0}),
),
),
(
"stage2_embedding_target_wgan",
lambda cfg: (
cfg["conditioning"]["particle"].__setitem__("type", "embedding"),
cfg["conditioning"]["material"].__setitem__("type", "embedding"),
cfg["stage2_model"].__setitem__("particle_type", {"target": "embedding", "lambda": 1.0}),
),
),
(
"stage2_embedding_target_flow",
lambda cfg: (
cfg["conditioning"]["particle"].__setitem__("type", "embedding"),
cfg["conditioning"]["material"].__setitem__("type", "embedding"),
cfg["stage2_model"].__setitem__("generator", "flow"),
cfg["stage2_model"].__setitem__("particle_type", {"target": "embedding", "lambda": 1.0}),
),
),
(
"ar_wgan_onehot",
lambda cfg: (
cfg["stage2_model"].__setitem__("decoder", "autoregressive"),
cfg["stage2_model"].__setitem__("particle_type", {"target": "onehot", "lambda": 1.0}),
),
),
(
"ar_wgan_physical",
lambda cfg: cfg["stage2_model"].__setitem__("decoder", "autoregressive"),
),
(
"ar_flow_onehot",
lambda cfg: (
cfg["stage2_model"].__setitem__("decoder", "autoregressive"),
cfg["stage2_model"].__setitem__("generator", "flow"),
cfg["stage2_model"].__setitem__("particle_type", {"target": "onehot", "lambda": 1.0}),
),
),
(
"ar_flow_embedding",
lambda cfg: (
cfg["conditioning"]["particle"].__setitem__("type", "embedding"),
cfg["conditioning"]["material"].__setitem__("type", "embedding"),
cfg["stage2_model"].__setitem__("decoder", "autoregressive"),
cfg["stage2_model"].__setitem__("generator", "flow"),
cfg["stage2_model"].__setitem__("particle_type", {"target": "embedding", "lambda": 1.0}),
),
),
(
"ar_stage2_only",
lambda cfg: (
cfg["stage1_model"].__setitem__("active", False),
cfg["stage2_model"].__setitem__("decoder", "autoregressive"),
),
),
(
"ar_mixed_stage1_wgan_stage2_flow_onehot",
lambda cfg: (
cfg["stage1_model"].__setitem__("generator", "wgan"),
cfg["stage2_model"].__setitem__("generator", "flow"),
cfg["stage2_model"].__setitem__("decoder", "autoregressive"),
cfg["stage2_model"].__setitem__("particle_type", {"target": "onehot", "lambda": 1.0}),
),
),
],
)
def test_train_end_to_end(label, mutate):
cfg = _base_cfg()
mutate(cfg)
with tempfile.TemporaryDirectory() as tmp:
out_dir = Path(tmp) / "run"
_run_train(cfg, out_dir)
assert (out_dir / "last.pt").exists()
assert (out_dir / "metrics.csv").exists()
ckpt = torch.load(out_dir / "last.pt", weights_only=False)
if cfg["stage1_model"]["active"]:
assert "model" in ckpt
else:
assert "model" not in ckpt
if cfg["stage2_model"]["active"]:
assert "sec_decoder" in ckpt
else:
assert "sec_decoder" not in ckpt
def test_train_resume_continues_from_checkpoint():
cfg = _base_cfg()
with tempfile.TemporaryDirectory() as tmp:
out_dir = Path(tmp) / "run"
_run_train(cfg, out_dir)
ckpt_before = torch.load(out_dir / "last.pt", weights_only=False)
assert ckpt_before["epoch"] == 2
cfg2 = copy.deepcopy(cfg)
cfg2["train"]["epochs"] = 3
_run_train(cfg2, out_dir, resume_path=out_dir / "last.pt")
ckpt_after = torch.load(out_dir / "last.pt", weights_only=False)
assert ckpt_after["epoch"] == 3
assert ckpt_after["global_step"] > ckpt_before["global_step"]
def test_train_raises_when_no_active_stage():
cfg = _base_cfg()
cfg["stage1_model"]["active"] = False
cfg["stage2_model"]["active"] = False
model_config = _model_config(cfg)
models = build_models(model_config)
critics = build_critics(model_config)
with tempfile.TemporaryDirectory() as tmp:
with pytest.raises(ValueError, match="no active stage"):
train(
cfg=cfg,
models=models,
critics=critics,
train_loader=_fake_batches(1, 8),
val_loader=_fake_batches(1, 8),
device=torch.device("cpu"),
out_dir=Path(tmp) / "run",
model_config=model_config,
total_train_batches=1,
)
def test_metrics_csv_columns_are_stage_prefixed():
cfg = _base_cfg()
with tempfile.TemporaryDirectory() as tmp:
out_dir = Path(tmp) / "run"
_run_train(cfg, out_dir)
header = (out_dir / "metrics.csv").read_text().splitlines()[0].split(",")
assert "stage1/train/loss" in header
assert "stage2/train/d_loss" in header
assert "val/loss" in header
assert "epoch" in header
def test_wgan_stage_trainer_skips_generator_step_when_no_grad_this_batch():
"""Regression test: on a non-generator-step batch, if this stage's model
has no n_sec_head (n_sec defaults to stage 2), g_loss is a
graph-less zero — .backward() must not be called on it."""
cfg = _base_cfg()
cfg["stage1_model"]["generator"] = "wgan"
model_config = _model_config(cfg)
models = build_models(model_config)
critics = build_critics(model_config)
assert models["stage1"] is not None and critics["stage1"] is not None
spec = StageSpec(
name="stage1",
is_stage2=False,
generator="wgan",
n_critic=1000, # never a generator step in this test
ema_decay=0.0,
steps_per_epoch=4,
)
trainer = WGANStageTrainer(spec, models["stage1"], critics["stage1"], torch.device("cpu"))
assert trainer.model.n_sec_head is None
batch = _fake_batches(1, 8)[0]
stats = trainer.step(batch, torch.device("cpu"), global_step=1)
assert stats["did_g_step"] is False
def test_flow_stage_trainer_ddpm_not_implemented_for_stage2():
spec = StageSpec(name="stage2", is_stage2=True, generator="ddpm", ddpm_n_steps=50, ema_decay=0.0)
with pytest.raises(NotImplementedError):
FlowDDPMStageTrainer(spec, torch.nn.Linear(1, 1), torch.device("cpu"))
# --- gitea #42: freeze / init_from -------------------------------------------
def _state_dict_clone(module):
return {k: v.clone() for k, v in module.state_dict().items()}
def _assert_state_dicts_equal(before, after, label):
for key, value in before.items():
assert torch.equal(value, after[key]), f"{label}: {key} changed while frozen"
def test_frozen_flow_stage_trainer_step_does_not_update_model_or_ema():
cfg = _base_cfg()
model_config = _model_config(cfg)
model = build_models(model_config)["stage1"]
assert model is not None
spec = StageSpec(name="stage1", is_stage2=False, generator="flow", freeze=True, ema_decay=0.999, steps_per_epoch=4)
trainer = FlowDDPMStageTrainer(spec, model, torch.device("cpu"))
assert trainer.ema_model is not None
model_before = _state_dict_clone(trainer.model)
ema_before = _state_dict_clone(trainer.ema_model)
for batch in _fake_batches(4, 8):
trainer.step(batch, torch.device("cpu"), global_step=1)
_assert_state_dicts_equal(model_before, trainer.model.state_dict(), "frozen flow model")
_assert_state_dicts_equal(ema_before, trainer.ema_model.state_dict(), "frozen flow ema")
def test_frozen_wgan_stage_trainer_step_does_not_update_generator_or_critic():
cfg = _base_cfg()
cfg["stage1_model"]["generator"] = "wgan"
model_config = _model_config(cfg)
models = build_models(model_config)
critics = build_critics(model_config)
assert models["stage1"] is not None and critics["stage1"] is not None
spec = StageSpec(
name="stage1",
is_stage2=False,
generator="wgan",
freeze=True,
n_critic=1, # a generator step every batch, so a bug would surface immediately
ema_decay=0.999,
steps_per_epoch=4,
)
trainer = WGANStageTrainer(spec, models["stage1"], critics["stage1"], torch.device("cpu"))
assert trainer.ema_model is not None
model_before = _state_dict_clone(trainer.model)
critic_before = _state_dict_clone(trainer.critic)
ema_before = _state_dict_clone(trainer.ema_model)
for global_step, batch in enumerate(_fake_batches(4, 8)):
trainer.step(batch, torch.device("cpu"), global_step=global_step)
_assert_state_dicts_equal(model_before, trainer.model.state_dict(), "frozen wgan generator")
_assert_state_dicts_equal(critic_before, trainer.critic.state_dict(), "frozen wgan critic")
_assert_state_dicts_equal(ema_before, trainer.ema_model.state_dict(), "frozen wgan ema")
@pytest.mark.parametrize("stage1_generator", ["flow", "wgan"])
def test_train_end_to_end_frozen_stage1_unchanged_while_stage2_trains(stage1_generator):
cfg = _base_cfg()
cfg["stage1_model"]["generator"] = stage1_generator
cfg["stage1_model"]["freeze"] = True
model_config = _model_config(cfg)
models = build_models(model_config)
critics = build_critics(model_config)
assert models["stage1"] is not None and models["stage2"] is not None
stage1_before = _state_dict_clone(models["stage1"])
stage2_before = _state_dict_clone(models["stage2"])
with tempfile.TemporaryDirectory() as tmp:
train(
cfg=cfg,
models=models,
critics=critics,
train_loader=_fake_batches(4, cfg["train"]["batch_size"]),
val_loader=_fake_batches(2, cfg["train"]["batch_size"], seed=1),
device=torch.device("cpu"),
out_dir=Path(tmp) / "run",
normalizer_dict={"cond": {}, "target": {}, "sec_phys": {}},
pdg_map={"22": 0},
mat_map={"G4_AIR": 0},
proc_map=None,
model_config=model_config,
total_train_batches=4,
)
_assert_state_dicts_equal(stage1_before, models["stage1"].state_dict(), "frozen stage1")
stage2_after = models["stage2"].state_dict()
assert any(not torch.equal(v, stage2_after[k]) for k, v in stage2_before.items()), (
"unfrozen stage2 should have trained"
)
def test_init_stages_from_checkpoints_loads_matching_stage_and_ema_weights(tmp_path):
cfg = _base_cfg()
model_config = _model_config(cfg)
source_models = build_models(model_config)
source_critics = build_critics(model_config)
source_trainers = build_stage_trainers(cfg, source_models, source_critics, torch.device("cpu"), 4)
source_stage1_ema = source_trainers["stage1"].ema_model
assert source_stage1_ema is not None
# Diverge the source's EMA from its raw weights so a same-vs-different
# check below actually distinguishes the two copy paths.
for p in source_stage1_ema.parameters():
p.data.add_(1.0)
ckpt_path = tmp_path / "source.pt"
ckpt = build_checkpoint(source_trainers, epoch=1, global_step=1, best_val_loss=0.0, extras={})
torch.save(ckpt, ckpt_path)
cfg2 = copy.deepcopy(cfg)
cfg2["stage1_model"]["init_from"] = str(ckpt_path)
dest_models = build_models(_model_config(cfg2))
dest_critics = build_critics(_model_config(cfg2))
dest_trainers = build_stage_trainers(cfg2, dest_models, dest_critics, torch.device("cpu"), 4)
loaded = init_stages_from_checkpoints(dest_trainers)
assert len(loaded) == 1 and "stage1" in loaded[0]
dest_stage1_ema = dest_trainers["stage1"].ema_model
assert dest_stage1_ema is not None
_assert_state_dicts_equal(
source_trainers["stage1"].model.state_dict(), dest_trainers["stage1"].model.state_dict(), "init_from raw"
)
_assert_state_dicts_equal(
source_stage1_ema.state_dict(),
dest_stage1_ema.state_dict(),
"init_from ema",
)
# stage2 has no init_from set -- untouched fresh init, not the source's.
stage2_matches_source = all(
torch.equal(v, dest_trainers["stage2"].model.state_dict()[k])
for k, v in source_trainers["stage2"].model.state_dict().items()
)
assert not stage2_matches_source
def test_run_train_job_stage1_init_from_freeze_produces_rollout_capable_checkpoint(tmp_path):
"""The exact scenario gitea #42 exists for: retrain stage 2 alone against
a fixed, known-good stage 1, and still get a checkpoint giant rollout can
load (checkpoint_io.load_for_inference with require_stage2=True)."""
normalizer_dict = {
"cond": Normalizer().fit(np.zeros((1, COND_DIM), dtype=np.float32)).to_dict(),
"target": Normalizer().fit(np.zeros((1, X_DIM), dtype=np.float32)).to_dict(),
"sec_phys": Normalizer().fit(np.zeros((1, 2), dtype=np.float32)).to_dict(),
}
cfg = _base_cfg()
source_out = tmp_path / "source"
_run_train(cfg, source_out, normalizer_dict=normalizer_dict)
source_ckpt = torch.load(source_out / "best.pt", weights_only=False)
cfg2 = copy.deepcopy(cfg)
cfg2["stage1_model"]["init_from"] = str(source_out / "best.pt")
cfg2["stage1_model"]["freeze"] = True
retrain_out = tmp_path / "retrain"
_run_train(cfg2, retrain_out, normalizer_dict=normalizer_dict)
ctx = load_for_inference(retrain_out / "best.pt", torch.device("cpu"), "rollout", require_stage2=True)
assert ctx.stage1 is not None and ctx.stage2 is not None
retrain_ckpt = torch.load(retrain_out / "best.pt", weights_only=False)
for key, value in source_ckpt["model"].items():
assert torch.equal(value, retrain_ckpt["model"][key]), f"frozen stage1 {key} drifted across the retrain"
def test_stage_spec_from_config_omitted_decoder_and_particle_type_match_default_config():
"""Regression for issues.md Issue 1: StageSpec.from_config's own fallback
defaults for stage2_model.decoder/particle_type must equal
DEFAULT_CONFIG's ("autoregressive" / "onehot"), not the old, now-wrong
("one_shot" / "physical") literals a .get(key, default) call used to
supply when a hand-built cfg omitted these keys."""
cfg = _base_cfg()
del cfg["stage2_model"]["decoder"]
del cfg["stage2_model"]["particle_type"]
spec = StageSpec.from_config(cfg, "stage2", is_stage2=True, steps_per_epoch=1)
assert spec.decoder == "autoregressive"
assert spec.particle_type.target == "onehot"
def _routed_stage1_trainer(lambda_balance, lambda_proc, lambda_entropy):
cfg = _base_cfg()
cfg["stage1_model"]["router"] = {
"enabled": True,
"type": "energy",
"n_experts": 3,
"temperature": 0.5,
"learn_centers": True,
"lambda_balance": lambda_balance,
"lambda_proc": lambda_proc,
"lambda_entropy": lambda_entropy,
}
model_config = _model_config(cfg)
models = build_models(model_config)
critics = build_critics(model_config)
trainers = build_stage_trainers(cfg, models, critics, torch.device("cpu"), total_train_batches=4)
return trainers["stage1"]
def test_router_aux_losses_skipped_when_lambda_zero_but_run_when_positive():
"""Gitea #31: FlowDDPMStageTrainer._compute must not call
router.balance_loss/classify_loss/entropy_loss when the corresponding
lambda is 0 (the default) -- those calls do their own router.gate(...)
forward pass that is wasted once the term is masked out of the total
loss anyway. Checked both ways: zero lambdas must skip all three calls,
positive lambdas must still make them (the guard must not accidentally
suppress the real path)."""
batch = _fake_batches(1, 4)[0]
device = torch.device("cpu")
trainer_zero = _routed_stage1_trainer(0.0, 0.0, 0.0)
router_zero = trainer_zero.router
router_zero.balance_loss = MagicMock(wraps=router_zero.balance_loss)
router_zero.classify_loss = MagicMock(wraps=router_zero.classify_loss)
router_zero.entropy_loss = MagicMock(wraps=router_zero.entropy_loss)
stats_zero = trainer_zero.step(batch, device, global_step=1)
assert router_zero.balance_loss.call_count == 0
assert router_zero.classify_loss.call_count == 0
assert router_zero.entropy_loss.call_count == 0
assert stats_zero["loss_balance"] == 0.0
assert stats_zero["loss_proc"] == 0.0
assert stats_zero["loss_entropy"] == 0.0
trainer_pos = _routed_stage1_trainer(0.1, 0.1, 0.01)
router_pos = trainer_pos.router
router_pos.balance_loss = MagicMock(wraps=router_pos.balance_loss)
router_pos.classify_loss = MagicMock(wraps=router_pos.classify_loss)
router_pos.entropy_loss = MagicMock(wraps=router_pos.entropy_loss)
trainer_pos.step(batch, device, global_step=1)
assert router_pos.balance_loss.call_count == 1
assert router_pos.classify_loss.call_count == 1
assert router_pos.entropy_loss.call_count == 1
# --- AR trainer wiring (v0.3.0 step 5) --------------------------------------
@pytest.mark.parametrize("teacher_forcing", ["always", "scheduled", "never"])
@pytest.mark.parametrize("history", ["markov", "attention"])
@pytest.mark.parametrize("stage2_generator", ["wgan", "flow"])
def test_build_stage_trainers_ar_scheduled_and_attention_step_runs(teacher_forcing, history, stage2_generator):
"""v0.3.0 step 7: history='attention' and teacher_forcing in
{'scheduled', 'never'} must actually train — a stage-2 AR trainer.step()
must run and produce a finite loss, for every {history} x
{teacher_forcing} x {generator} combination."""
cfg = _base_cfg()
cfg["stage2_model"]["decoder"] = "autoregressive"
cfg["stage2_model"]["generator"] = stage2_generator
cfg["stage2_model"]["autoregressive"] = {
"history": history,
"teacher_forcing": teacher_forcing,
"tf_p_start": 1.0,
"tf_p_end": 0.0,
"attn_n_heads": 2,
"attn_n_layers": 1,
}
model_config = _model_config(cfg)
models = build_models(model_config)
critics = build_critics(model_config)
trainers = build_stage_trainers(cfg, models, critics, torch.device("cpu"), total_train_batches=4)
trainer = trainers["stage2"]
batch = _fake_batches(1, 4)[0]
stats = trainer.step(batch, torch.device("cpu"), global_step=1)
loss_key = "g_loss" if stage2_generator == "wgan" else "loss"
assert math.isfinite(stats[loss_key])
@pytest.mark.parametrize("stage2_generator", ["wgan", "flow"])
def test_train_end_to_end_ar_attention_history_scheduled_teacher_forcing(
stage2_generator,
):
"""Full `train()` run (not just one `trainer.step()` call) with
history='attention' AND teacher_forcing='scheduled' together — the
combination v0.3.0 step 7 exists to land — must complete and write a
checkpoint + metrics.csv with finite losses throughout."""
cfg = _base_cfg()
cfg["stage2_model"]["decoder"] = "autoregressive"
cfg["stage2_model"]["generator"] = stage2_generator
cfg["stage2_model"]["autoregressive"] = {
"history": "attention",
"teacher_forcing": "scheduled",
"tf_p_start": 1.0,
"tf_p_end": 0.0,
"attn_n_heads": 2,
"attn_n_layers": 1,
}
with tempfile.TemporaryDirectory() as tmp:
out_dir = Path(tmp) / "run"
_run_train(cfg, out_dir)
assert (out_dir / "last.pt").exists()
with open(out_dir / "metrics.csv", newline="") as f:
rows = list(csv.DictReader(f))
assert len(rows) == cfg["train"]["epochs"]
loss_col = "stage2/train/g_loss" if stage2_generator == "wgan" else "stage2/train/loss"
assert all(math.isfinite(float(r[loss_col])) for r in rows)
def test_ar_wgan_onehot_grad_norm_instrumentation_populates_metrics():
"""Differentiability validation-obligation instrumentation: the
trunk-gradient-norm-by-slice columns must appear and actually fire for
generator='wgan' + particle_type.target='onehot' under decoder=
'autoregressive' (added at v0.3.0 step 5 to accrue evidence during the
architecture comparison)."""
cfg = _base_cfg()
cfg["stage2_model"]["decoder"] = "autoregressive"
cfg["stage2_model"]["particle_type"] = {"target": "onehot", "lambda": 1.0}
with tempfile.TemporaryDirectory() as tmp:
out_dir = Path(tmp) / "run"
_run_train(cfg, out_dir)
with open(out_dir / "metrics.csv", newline="") as f:
rows = list(csv.DictReader(f))
assert "stage2/train/grad_norm_type_slice" in rows[0]
assert "stage2/train/grad_norm_cont_slice" in rows[0]
assert any(float(r["stage2/train/grad_norm_type_slice"]) > 0 for r in rows)
assert any(float(r["stage2/train/grad_norm_cont_slice"]) > 0 for r in rows)
def test_wgan_onehot_one_shot_also_gets_grad_norm_instrumentation():
"""The instrumentation is decoder-agnostic — one_shot + wgan + onehot
must populate the same columns."""
cfg = _base_cfg()
cfg["stage2_model"]["particle_type"] = {"target": "onehot", "lambda": 1.0}
with tempfile.TemporaryDirectory() as tmp:
out_dir = Path(tmp) / "run"
_run_train(cfg, out_dir)
with open(out_dir / "metrics.csv", newline="") as f:
rows = list(csv.DictReader(f))
assert any(float(r["stage2/train/grad_norm_type_slice"]) > 0 for r in rows)
assert any(float(r["stage2/train/grad_norm_cont_slice"]) > 0 for r in rows)
# --- n_sec.mode = "stop_token" (gitea #40) ----------------------------------
def _stop_token_cfg():
cfg = _base_cfg()
cfg["stage2_model"]["decoder"] = "autoregressive"
cfg["stage2_model"]["n_sec"] = {"mode": "stop_token", "lambda": 0.1}
return cfg
@pytest.mark.parametrize("stage2_generator", ["wgan", "flow"])
def test_build_stage_trainers_stop_token_step_runs(stage2_generator):
"""A stop_token AR stage-2 trainer.step() must run and emit a finite
loss_stop for both non-adversarial (flow) and WGAN generators — the two
trainer subclasses wire the stop head's BCE term in independently."""
cfg = _stop_token_cfg()
cfg["stage2_model"]["generator"] = stage2_generator
model_config = _model_config(cfg)
models = build_models(model_config)
critics = build_critics(model_config)
trainers = build_stage_trainers(cfg, models, critics, torch.device("cpu"), total_train_batches=4)
trainer = trainers["stage2"]
batch = _fake_batches(1, 4)[0]
stats = trainer.step(batch, torch.device("cpu"), global_step=1)
assert math.isfinite(stats["loss_stop"])
assert math.isfinite(stats["stop_acc"])
def test_stop_token_model_has_stop_head_not_n_sec_head():
cfg = _stop_token_cfg()
model_config = _model_config(cfg)
models = build_models(model_config)
stage2 = models["stage2"]
assert isinstance(stage2, Stage2Autoregressive)
assert stage2.n_sec_head is None
assert stage2.stop_head is not None
def test_head_mode_model_has_n_sec_head_not_stop_head():
"""Sanity check on the other side of the gate — the default 'head' mode
must be unaffected by the stop_head plumbing."""
cfg = _base_cfg()
cfg["stage2_model"]["decoder"] = "autoregressive"
model_config = _model_config(cfg)
models = build_models(model_config)
stage2 = models["stage2"]
assert isinstance(stage2, Stage2Autoregressive)
assert stage2.n_sec_head is not None
assert stage2.stop_head is None
def test_train_end_to_end_stop_token():
"""Full train() run with n_sec.mode='stop_token' must complete and write
a checkpoint + metrics.csv with finite losses throughout."""
cfg = _stop_token_cfg()
with tempfile.TemporaryDirectory() as tmp:
out_dir = Path(tmp) / "run"
_run_train(cfg, out_dir)
assert (out_dir / "last.pt").exists()
with open(out_dir / "metrics.csv", newline="") as f:
rows = list(csv.DictReader(f))
assert len(rows) == cfg["train"]["epochs"]
assert all(math.isfinite(float(r["stage2/train/loss_stop"])) for r in rows)
def test_wgan_physical_omits_grad_norm_slice_columns():
cfg = _base_cfg() # _base_cfg's stage2_model.particle_type.target is "physical"
with tempfile.TemporaryDirectory() as tmp:
out_dir = Path(tmp) / "run"
_run_train(cfg, out_dir)
header = (out_dir / "metrics.csv").read_text().splitlines()[0].split(",")
assert "stage2/train/grad_norm_type_slice" not in header
assert "stage2/train/grad_norm_cont_slice" not in header
# --- stage2_model.stage1_context = "sampled" (gitea #41) --------------------
def _sampled_ctx_cfg(ema_decay=0.999):
cfg = _base_cfg()
cfg["stage1_model"]["generator"] = "flow"
cfg["stage2_model"]["generator"] = "flow"
cfg["stage2_model"]["stage1_context"] = "sampled"
cfg["stage2_model"]["ctx_p_start"] = 0.0
cfg["stage2_model"]["ctx_p_end"] = 0.0
cfg["train"]["ema_decay"] = ema_decay
return cfg
def _build_sampled_trainers(cfg):
model_config = _model_config(cfg)
models = build_models(model_config)
critics = build_critics(model_config)
return build_stage_trainers(cfg, models, critics, torch.device("cpu"), total_train_batches=4)
def test_build_stage_trainers_attaches_stage1_only_under_sampled():
trainers = _build_sampled_trainers(_sampled_ctx_cfg())
assert trainers["stage2"].stage1_source is trainers["stage1"]
assert trainers["stage1"].stage1_source is None
def test_build_stage_trainers_leaves_stage1_source_none_under_truth():
"""Regression guard for the old silent no-op: 'truth' (the default) must
never attach a stage1_source, so _stage1_context short-circuits without
ever calling sample_stage1."""
cfg = _base_cfg()
trainers = _build_sampled_trainers(cfg)
assert trainers["stage2"].stage1_source is None
def test_stage1_context_sampled_calls_sample_stage1_and_differs_from_truth():
cfg = _sampled_ctx_cfg()
trainers = _build_sampled_trainers(cfg)
stage1, stage2 = trainers["stage1"], trainers["stage2"]
batch = _fake_batches(1, 4)[0]
cond_cont, cond_cat, x1_s1 = batch.cond_cont, batch.cond_cat, batch.target_s1
with patch("giant.training.trainers.sample_stage1", wraps=trainers_sample_stage1) as spy:
ctx = stage2._stage1_context(x1_s1, cond_cont, cond_cat, epoch=0)
assert spy.call_count == 1
assert spy.call_args.args[0] is stage1.sampling_model()
assert not torch.equal(ctx, x1_s1)
def test_stage1_context_truth_default_never_calls_sample_stage1():
cfg = _base_cfg()
trainers = _build_sampled_trainers(cfg)
stage2 = trainers["stage2"]
batch = _fake_batches(1, 4)[0]
cond_cont, cond_cat, x1_s1 = batch.cond_cont, batch.cond_cat, batch.target_s1
with patch("giant.training.trainers.sample_stage1", wraps=trainers_sample_stage1) as spy:
ctx = stage2._stage1_context(x1_s1, cond_cont, cond_cat, epoch=0)
assert spy.call_count == 0
assert torch.equal(ctx, x1_s1)
def test_stage1_context_val_epoch_none_uses_ground_truth_even_under_sampled():
cfg = _sampled_ctx_cfg()
trainers = _build_sampled_trainers(cfg)
stage2 = trainers["stage2"]
batch = _fake_batches(1, 4)[0]
cond_cont, cond_cat, x1_s1 = batch.cond_cont, batch.cond_cat, batch.target_s1
with patch("giant.training.trainers.sample_stage1", wraps=trainers_sample_stage1) as spy:
ctx = stage2._stage1_context(x1_s1, cond_cont, cond_cat, epoch=None)
assert spy.call_count == 0
assert torch.equal(ctx, x1_s1)
def test_stage1_context_sampled_preserves_stage1_training_mode():
"""Every sampler in giant/sample.py flips its model to .eval() as a side
effect with no restore of its own (see sample_flow). Sampling from the
RAW stage-1 model (ema_decay=0, so sampling_model() returns self.model,
the same weights the stage-1 trainer is actively training on) must not
silently leave it in eval mode for the rest of the epoch's stage-1
updates."""
cfg = _sampled_ctx_cfg(ema_decay=0.0)
trainers = _build_sampled_trainers(cfg)
stage1, stage2 = trainers["stage1"], trainers["stage2"]
stage1.train_mode()
assert stage1.model.training
batch = _fake_batches(1, 4)[0]
cond_cont, cond_cat, x1_s1 = batch.cond_cont, batch.cond_cat, batch.target_s1
stage2._stage1_context(x1_s1, cond_cont, cond_cat, epoch=0)
assert stage1.model.training
@pytest.mark.parametrize("stage2_generator", ["wgan", "flow"])
def test_build_stage_trainers_sampled_step_runs(stage2_generator):
"""Both trainer subclasses' call sites (FlowDDPMStageTrainer._compute,
WGANStageTrainer.step) must run end to end under 'sampled' and produce a
finite loss."""
cfg = _sampled_ctx_cfg()
cfg["stage2_model"]["generator"] = stage2_generator
trainers = _build_sampled_trainers(cfg)
trainer = trainers["stage2"]
batch = _fake_batches(1, 4)[0]
stats = trainer.step(batch, torch.device("cpu"), global_step=1)
loss_key = "g_loss" if stage2_generator == "wgan" else "loss"
assert math.isfinite(stats[loss_key])
def test_train_end_to_end_stage1_context_sampled():
"""Full train() run with stage1_context='sampled' must complete and
write a checkpoint + metrics.csv with finite losses throughout."""
cfg = _sampled_ctx_cfg()
with tempfile.TemporaryDirectory() as tmp:
out_dir = Path(tmp) / "run"
_run_train(cfg, out_dir)
assert (out_dir / "last.pt").exists()
with open(out_dir / "metrics.csv", newline="") as f:
rows = list(csv.DictReader(f))
assert len(rows) == cfg["train"]["epochs"]
assert all(math.isfinite(float(r["stage2/train/loss"])) for r in rows)