feat(cluster): 加 --train-only,自监督训练与聚类可分两步跑

engine/simclr.py 与 engine/cluster.py 本来就互不引用,唯一接口是
simclr_backbone.pth;耦合只在 CLI——method=simclr 会训练完直接聚类。
此前"只聚类"可以用 simclr.checkpoint 做到,"只训练"没有办法。

- --train-only:训练存完权重即退出,不抽特征也不聚类,并打印下一步的聚类命令
- 与 method=pretrained / simclr.checkpoint / --sweep-k 组合时立刻报错说明原因,
  而不是跑完才发现没有产出
- 典型用法:GPU 机器上 --train-only 跑几十小时,之后拿权重反复调 k,每次约 1 分钟

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
This commit is contained in:
Shaun Zhou
2026-09-07 11:38:59 +08:00
co-authored by Claude Opus 5
parent 5d395b7c25
commit 0f5bb4a5c0
3 changed files with 149 additions and 1 deletions
+22
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@@ -359,6 +359,28 @@ uv run python scripts/cluster_unlabeled.py --config configs/cluster/film.yaml \
> **`checkpoint`** = 有权重就**跳过训练**直接聚类(要 `simclr_backbone.pth`)。
> 拿 `simclr_backbone.pth` 去 `resume` 会报错,因为它不含投影头和优化器状态。
#### 训练与聚类分开跑
自监督训练和聚类在代码上本来就是解耦的(`engine/simclr.py` 与 `engine/cluster.py`
互不引用,唯一接口是 `simclr_backbone.pth`),只是默认一条命令串起来跑。
需要分两步时——比如在 GPU 机器上专心训练几十小时,之后在别处反复调 k——用
`--train-only` 断开:
```bash
# 第一步:只训练,存完权重就退出,不抽特征也不聚类
uv run python scripts/cluster_unlabeled.py --config configs/cluster/film_simclr_resnet18.yaml \
--work-dir runs/simclr_r18 --train-only --set simclr.epochs=40
# 第二步:只聚类,想换几次 k 就跑几次,每次约 1 分钟
uv run python scripts/cluster_unlabeled.py --config configs/cluster/film_simclr_resnet18.yaml \
--work-dir runs/simclr_r18_k4 \
--set simclr.checkpoint=runs/simclr_r18/simclr_backbone.pth --num-clusters 4
```
第一步只产出 `simclr_backbone.pth` 与 `simclr_last.pth`,没有 `assignments.csv` 之类。
`--train-only` 遇到 `method=pretrained`(没东西可训)、`simclr.checkpoint`(会跳过训练)
或 `--sweep-k`(要靠聚类才能扫)都会直接报错,不会跑完才发现什么都没产出。
#### 第二步:复用权重重新聚类
想换簇数或改聚类参数时**不必重训**——把权重路径填进 `simclr.checkpoint` 就会跳过训练
+34 -1
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@@ -389,6 +389,11 @@ def main() -> int:
parser.add_argument(
"--sweep-k", default=None, metavar="A-B", help="只扫簇数(如 2-8)打印指标表,不产出分组"
)
parser.add_argument(
"--train-only",
action="store_true",
help="只做 SimCLR 自监督训练,存完权重就退出,不抽特征也不聚类",
)
args = parser.parse_args()
cfg = load_config(args.config, args.set)
@@ -409,18 +414,46 @@ def main() -> int:
logger.error("%s", exc)
return 1
method = str(cfg.get("method", "pretrained"))
if args.train_only:
# 这三种组合下 --train-only 要么无事可做、要么与另一个"提前结束"的开关打架,
# 与其跑完才发现什么都没产出,不如立刻说清楚
if method != "simclr":
logger.error("--train-only 只对 method=simclr 有意义,当前 method=%s(没有要训练的东西)", method)
return 1
if cfg.get("simclr", {}).get("checkpoint"):
logger.error(
"--train-only 与 simclr.checkpoint 冲突:checkpoint 会跳过训练,"
"加上 --train-only 就什么都不会做。想接着上次练请改用 simclr.resume。"
)
return 1
if args.sweep_k:
logger.error("--train-only 与 --sweep-k 不能同时用:前者不聚类,后者要靠聚类才能扫")
return 1
dataset = build_dataset(dict(cfg["dataset"]))
logger.info(
"扫描到 %d 张图,来自 %d 个目录;簇数 %d,method=%s,设备 %s",
len(dataset),
len({dataset.source_dir(path) for path in dataset.images}),
num_clusters,
cfg.get("method", "pretrained"),
method,
describe_device(device),
)
encoder = build_encoder(cfg, device, work_dir)
if args.train_only:
weights = work_dir / "simclr_backbone.pth"
logger.info("--train-only:训练完成,未做聚类。权重在 %s", weights)
logger.info(
"接着聚类:uv run python scripts/cluster_unlabeled.py --config %s "
"--work-dir <新目录> --set simclr.checkpoint=%s",
cfg.get("config_path", "<配置>"),
weights,
)
return 0
from torch.utils.data import DataLoader
loader = DataLoader(
+93
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@@ -480,6 +480,99 @@ def test_cluster_script_simclr_branch_end_to_end(tiny_image_dir, tmp_path, monke
assert (work_dir / "clusters" / "cluster_00").is_dir()
def _cluster_argv(work_dir, image_dir, *extra):
return [
"cluster_unlabeled.py", "--config", "configs/cluster/film.yaml",
"--work-dir", str(work_dir), "--root", str(image_dir), "--set",
"device=cpu", "loader.num_workers=0", "loader.batch_size=4",
"num_clusters=2", "n_init=2", *extra,
]
def test_train_only_stops_before_clustering(tiny_image_dir, tmp_path, monkeypatch):
"""--train-only 只训练存权重,不抽特征也不聚类。"""
sys.path.insert(0, "scripts")
import cluster_unlabeled as cu
work_dir = tmp_path / "train_only"
monkeypatch.setattr(
sys, "argv",
[*_cluster_argv(work_dir, tiny_image_dir,
"method=simclr", "simclr.epochs=1", "simclr.batch_size=4",
"simclr.backbone.widths=[8,16]", "simclr.backbone.depths=[1,1]",
"simclr.projection.hidden_channels=16", "simclr.projection.out_channels=8"),
"--train-only"],
)
assert cu.main() == 0
assert (work_dir / "simclr_backbone.pth").exists()
assert (work_dir / "simclr_last.pth").exists() # 续训状态照常落盘
for produced_by_clustering in ("assignments.csv", "summary.json", "cluster_scatter.png", "clusters"):
assert not (work_dir / produced_by_clustering).exists(), produced_by_clustering
def test_train_only_then_cluster_only(tiny_image_dir, tmp_path, monkeypatch):
"""训练与聚类可以分两次跑:第一次只训练,第二次用 checkpoint 只聚类。"""
sys.path.insert(0, "scripts")
import cluster_unlabeled as cu
train_dir = tmp_path / "phase1"
monkeypatch.setattr(
sys, "argv",
[*_cluster_argv(train_dir, tiny_image_dir,
"method=simclr", "simclr.epochs=1", "simclr.batch_size=4",
"simclr.backbone.widths=[8,16]", "simclr.backbone.depths=[1,1]",
"simclr.projection.hidden_channels=16", "simclr.projection.out_channels=8"),
"--train-only"],
)
assert cu.main() == 0
cluster_dir = tmp_path / "phase2"
monkeypatch.setattr(
sys, "argv",
_cluster_argv(cluster_dir, tiny_image_dir,
"method=simclr",
f"simclr.checkpoint={train_dir / 'simclr_backbone.pth'}",
"simclr.backbone.widths=[8,16]", "simclr.backbone.depths=[1,1]"),
)
assert cu.main() == 0
assert (cluster_dir / "assignments.csv").exists()
assert not (cluster_dir / "simclr_backbone.pth").exists(), "第二步不该重新训练"
@pytest.mark.parametrize(
"extra,reason",
[
([], "method=pretrained 没有要训练的东西"),
(["method=simclr", "simclr.checkpoint=whatever.pth"], "checkpoint 会跳过训练"),
],
)
def test_train_only_rejects_meaningless_combinations(
tiny_image_dir, tmp_path, monkeypatch, extra, reason
):
"""这些组合下 --train-only 什么都不会做,应当立刻报错而不是跑完才发现没产出。"""
sys.path.insert(0, "scripts")
import cluster_unlabeled as cu
monkeypatch.setattr(
sys, "argv", [*_cluster_argv(tmp_path / "bad", tiny_image_dir, *extra), "--train-only"]
)
assert cu.main() == 1, reason
def test_train_only_conflicts_with_sweep_k(tiny_image_dir, tmp_path, monkeypatch):
sys.path.insert(0, "scripts")
import cluster_unlabeled as cu
monkeypatch.setattr(
sys, "argv",
[*_cluster_argv(tmp_path / "bad", tiny_image_dir, "method=simclr"),
"--train-only", "--sweep-k", "2-4"],
)
assert cu.main() == 1
def test_scatter_plot_is_written_next_to_previews(tiny_image_dir, tmp_path, monkeypatch):
"""cluster_scatter.png 要和 preview 拼图落在同一级目录。"""
sys.path.insert(0, "scripts")