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XRDMatch

1.模型训练与评估

    python main.py
    python main.py --mode eval --exp_id x --epoch x

2.背景简介

XRDMatch 是一个基于 PaddleScience 的 XRD 数据半监督学习示例,使用 FlexMatch 算法进行材料分类。该示例展示了如何使用少量有标签数据和大量无标签数据来训练高性能的分类模型,特别适用于材料科学中的 XRD 谱线分析。

X射线衍射(XRD)是材料科学中重要的表征技术,能够提供材料的晶体结构信息。在实际应用中,获取大量有标签的 XRD 数据成本高昂且耗时,而半监督学习可以充分利用大量无标签数据来提升模型性能,降低标注成本。

本工作目的是利用锂离子固态电解质材料的XRD数据训练,得到相应的结构和性能关系。通过FlexMatch算法,结合数据增强、伪标签生成、动态阈值和一致性正则化等技术,实现高效的半监督学习。

3.模型原理

该方法的主要思想是通过卷积神经网络建立XRD谱线数据与材料性能之间的非线性映射关系。模型采用VGG网络作为特征提取器,结合FlexMatch半监督学习算法,能够有效利用大量无标签数据提升模型性能。

本案例采用VGG网络作为基础模型架构,主要包括以下几个部分:

  1. 输入层:接收 1×4501 的 XRD 谱线数据
  2. 卷积层:多层卷积块,提取局部特征模式
  3. 池化层:降维和特征聚合
  4. 全连接层:特征映射到分类结果
  5. 输出层:2类分类(正类/负类)

通过FlexMatch算法,模型能够: - 基于弱增强数据生成伪标签 - 使用强增强数据进行一致性训练 - 动态调整选择阈值,平衡各类别样本

3.1数据格式说明

数据集包含材料XRD谱线数据和对应的性能标签: - 数据连接:

https://paddle-org.bj.bcebos.com/paddlescience/datasets/xrdmatch/lbs.csv
https://paddle-org.bj.bcebos.com/paddlescience/datasets/xrdmatch/ulbs.csv
- xrd_data/lbs.csv: 有标签数据 - 包含样本名称、ID、标签和 XRD 谱线数据(4501维特征) - 标签:0(正类)、1(负类)

  • xrd_data/ulbs.csv: 无标签数据
  • 包含样本名称、ID 和 XRD 谱线数据(4501维特征)
  • 无标签信息,用于半监督学习

3.2数据预处理与增强策略

  1. 归一化:将 XRD 强度值归一化到 [0,1] 范围
  2. 噪声处理:去除低强度噪声(阈值 < 0.1)
  3. 数据增强
  4. 弱增强:添加少量噪声(10%)和位移(100像素)
  5. 强增强:缩放(15%)、消除(15%)、大幅位移(200像素)和噪声(20%)
    examples/xrdmatch/main.py
    def normdata(data):
        # Normalize data to [0, 1] range
        min_x = min(data)
        max_x = max(data)
        norm = max_x - min_x
        data = (data - min_x) / norm
        return data
    
    
    def data_zero(data):
        # Set small values (< 0.1) to zero for noise reduction
        num = len(data)
        for i in range(num):
            if data[i] < 0.1:
                data[i] = 0
        return data
    
    
    def weak_augdata(data, config=None):
        # Weak data augmentation: noise and shift
        if config is not None:
            w_noise_ratio = config["AUGMENTATION"]["weak_aug"]["noise_ratio"]
            w_noise_peak = config["AUGMENTATION"]["weak_aug"]["noise_peak"]
            w_move_gap = config["AUGMENTATION"]["weak_aug"]["move_gap"]
        else:
            w_noise_ratio = 0.1
            w_noise_peak = 0.05
            w_move_gap = 100
        ratio = np.random.random()
        if ratio <= 0.5:
            index = np.nonzero(data == 0)[0]
            idx_num = len(index)
            noise_num = int(idx_num * w_noise_ratio * np.random.random())
            np.random.shuffle(index)
            for i in index[:noise_num]:
                data[i] = np.random.random() * w_noise_peak
    
        ratio = np.random.random()
        if ratio <= 0.5:
            cut = np.random.randint(50, w_move_gap, 1)[0]
            if ratio <= 0.5:
                out = 4501 - cut
                data = np.append(np.zeros(cut), data[:out])
            else:
                data = np.append(data[cut:], np.zeros(cut))
    
        return data
    

3.3自定义数据集类

examples/xrdmatch/main.py
class XRDDataset(paddle.io.Dataset):
    def __init__(
        self,
        data,
        target,
        transform=None,
        is_ulb=False,
        strong_transform=None,
        config=None,
    ):
        super().__init__()
        self.data = data
        self.target = target
        self.transform = transform
        self.is_ulb = is_ulb
        self.strong_transform = strong_transform
        self.config = config

    def __getitem__(self, index):
        data = self.data[index]
        target = self.target[index]

        if self.is_ulb:
            x_ulb_w = self.transform(data, self.config)
            x_ulb_s = (
                self.strong_transform(data, self.config)
                if self.strong_transform
                else x_ulb_w
            )

            return {"idx_ulb": index, "x_ulb_w": x_ulb_w, "x_ulb_s": x_ulb_s}
        else:
            x_lb = self.transform(data, self.config)
            y_lb = paddle.to_tensor(target, dtype="int64")

            return {"idx_lb": index, "x_lb": x_lb, "y_lb": y_lb}

    def __len__(self):
        return len(self.data)

3.4 FlexMatch 半监督损失函数

  1. 有标签数据训练:使用交叉熵损失进行监督学习
  2. 无标签数据处理
  3. 生成弱增强和强增强版本
  4. 基于弱增强版本生成伪标签
  5. 使用强增强版本进行一致性训练
  6. 动态阈值:根据类别置信度动态调整选择阈值
    examples/xrdmatch/main.py
    class FlexMatchLoss:
        def __init__(self, config):
            self.T = getattr(config, "T", 0.5)
            self.p_cutoff = getattr(config, "p_cutoff", 0.95)
            self.hard_label = getattr(config, "hard_label", True)
            self.thresh_warmup = getattr(config, "thresh_warmup", True)
            self.lambda_u = getattr(config, "ulb_loss_ratio", 1.0)
            self.num_classes = getattr(config, "num_classes", 2)
            self.mask_acc = np.zeros(self.num_classes, dtype=np.float32)
            self.mask_cnt = np.zeros(self.num_classes, dtype=np.float32)
            self.criterion = paddle.nn.CrossEntropyLoss()
    
        def gen_pseudo_label(self, logits):
            logits_scaled = logits / self.T
            logits_max = paddle.max(logits_scaled, axis=-1, keepdim=True)
            logits_stable = logits_scaled - logits_max
            probs = paddle.nn.functional.softmax(logits_stable, axis=-1)
    
            if self.hard_label:
                pseudo_label = paddle.argmax(probs, axis=-1)
            else:
                pseudo_label = probs
            max_probs = paddle.max(probs, axis=-1)
            return pseudo_label, max_probs
    
        def get_mask(self, max_probs, pseudo_label):
            if self.thresh_warmup and self.mask_cnt.sum() > 0:
                class_acc = self.mask_acc / (self.mask_cnt + 1e-8)
                class_idx = pseudo_label.astype("int64")
                adaptive_threshold = self.p_cutoff * (
                    class_acc[class_idx] / (2.0 - class_acc[class_idx])
                )
                mask = (max_probs >= adaptive_threshold).astype("float32")
            else:
                mask = (max_probs >= self.p_cutoff).astype("float32")
    
            if self.thresh_warmup:
                for c in range(self.num_classes):
                    class_mask = (pseudo_label == c).astype("float32")
                    self.mask_acc[c] += float((mask * class_mask).sum().numpy())
                    self.mask_cnt[c] += float(class_mask.sum().numpy())
            return mask
    
        def __call__(self, model_output, batch):
            if "x_lb" in batch and "y_lb" in batch:
                logits_lb = model_output["logits"]
                loss_lb = self.criterion(logits_lb, batch["y_lb"])
            else:
                loss_lb = paddle.to_tensor(0.0)
    
            if "x_ulb_w" in batch and "x_ulb_s" in batch:
                with paddle.no_grad():
                    logits_ulb_w = (
                        model_output["logits_ulb_w"]
                        if "logits_ulb_w" in model_output
                        else model_output["logits"]
                    )
                    pseudo_label, max_probs = self.gen_pseudo_label(logits_ulb_w)
                    mask = self.get_mask(
                        max_probs,
                        pseudo_label
                        if self.hard_label
                        else paddle.argmax(pseudo_label, axis=-1),
                    )
                logits_ulb_s = (
                    model_output["logits_ulb_s"]
                    if "logits_ulb_s" in model_output
                    else model_output["logits"]
                )
                if self.hard_label:
                    loss_ulb = paddle.nn.functional.cross_entropy(
                        logits_ulb_s, pseudo_label, reduction="none"
                    )
                else:
                    loss_ulb = paddle.nn.functional.kl_div(
                        paddle.nn.functional.log_softmax(logits_ulb_s, axis=-1),
                        pseudo_label,
                        reduction="none",
                    ).sum(axis=-1)
                loss_ulb = (
                    (loss_ulb * mask).mean() if mask.sum() > 0 else paddle.to_tensor(0.0)
                )
            else:
                loss_ulb = paddle.to_tensor(0.0)
            total_loss = loss_lb + self.lambda_u * loss_ulb
            return {"loss": total_loss, "loss_lb": loss_lb, "loss_ulb": loss_ulb}
    

3.5 损失函数

total_loss = loss_lb + lambda_u * loss_ulb

其中: - loss_lb: 有标签数据的交叉熵损失 - loss_ulb: 无标签数据的一致性损失 - lambda_u: 无标签损失权重(默认1.0)

3.6 训练配置

  • 优化器:AdamW (lr=3e-4, weight_decay=0.01)
  • 批次大小:有标签32,无标签96
  • 实验次数:100次独立实验
  • 训练轮数:每个实验100轮(每轮10个迭代)
  • 数据划分:正类前20个,负类前75个用于训练
  • 模型保存:仅当F1分数≥0.7时保存模型

3.7 评估指标

  • 准确率 (Accuracy):正确分类的样本比例
  • 精确率 (Precision):预测为正类中实际为正类的比例
  • 召回率 (Recall):实际正类中被正确预测的比例
  • F1 分数 (F1-Score):精确率和召回率的调和平均
  • 混淆矩阵 (Confusion Matrix):各类别预测结果的详细分布
  • 评估方法:支持训练时评估和独立评估两种模式
  • 训练时评估:在训练过程中自动调用,将日志保存到每个实验的 saved_models_ppsci/exp_*/log.txt 文件中
  • 独立评估:使用 --mode eval 参数对已保存的模型进行评估,结果保存到 eval_log.txt 文件中
  • 模型保存策略:仅当F1分数≥0.7时保存模型
  • 内置评估实现:该函数会在训练过程中自动调用,并将日志保存到每个实验的 saved_models_ppsci/exp_*/log.txt 文件中。代码实现:
    examples/xrdmatch/main.py
    def evaluate(self, eval_loader, log_file=None):
        self.model.eval()
        y_true = []
        y_pred = []
    
        with paddle.no_grad():
            for batch in eval_loader:
                x = batch["x_lb"]
                y = batch["y_lb"]
    
                logits = self.model(x)["logits"]
                pred = paddle.argmax(logits, axis=1)
    
                y_true.extend(y.numpy().tolist())
                y_pred.extend(pred.numpy().tolist())
    
        y_true = np.array(y_true)
        y_pred = np.array(y_pred)
    
        if len(y_true) == 0 or len(y_pred) == 0:
            log_info("Warning: Empty evaluation data", log_file)
            result_dict = {"acc": 0.0, "precision": 0.0, "recall": 0.0, "f1": 0.0}
            log_info("confusion matrix", log_file)
            log_info("[]", log_file)
            log_info("evaluation metric", log_file)
            for key, item in result_dict.items():
                log_info(f"{key}: {item:.4f}", log_file)
            self.model.train()
            return result_dict
    
        acc = accuracy_score(y_true, y_pred)
        precision = precision_score(y_true, y_pred, average="macro")
        recall = recall_score(y_true, y_pred, average="macro")
        f1 = f1_score(y_true, y_pred, average="macro")
        cf_mat = confusion_matrix(y_true, y_pred, normalize="true")
    
        log_info("confusion matrix", log_file)
        log_info(str(cf_mat), log_file)
        result_dict = {"acc": acc, "precision": precision, "recall": recall, "f1": f1}
        log_info("evaluation metric", log_file)
        for key, item in result_dict.items():
            log_info(f"{key}: {item:.4f}", log_file)
    
        self.model.train()
    
        return result_dict
    

4.结果示例

训练日志示例

Epoch: 0
[2025-8-27 02:40:12,747 INFO] confusion matrix
[2025-8-27 02:40:12,748 INFO] [[0.22222222 0.77777778]
 [0.2        0.8       ]]
[2025-8-27 02:40:12,748 INFO] evaluation metric
[2025-8-27 02:40:12,748 INFO] acc: 0.7188
[2025-8-27 02:40:12,748 INFO] precision: 0.5083
[2025-8-27 02:40:12,750 INFO] recall: 0.5111
[2025-8-27 02:40:12,750 INFO] f1: 0.5060
F1 score 0.5060 < 0.7, model not saved at epoch 0

性能指标

在标准测试集上的典型性能:

指标
准确率 0.797
精确率 0.673
召回率 0.789
F1分数 0.695

评估日志示例

Evaluating experiment 0 epoch 11 model...
Starting prediction...
confusion matrix
[[0.77777778 0.22222222]
 [0.16363636 0.83636364]]
evaluation metric
acc: 0.6480
precision: 0.6480
recall: 0.6480
f1: 0.6480

5.完整代码

examples/xrdmatch/main.py
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import argparse
import datetime
import os
import random

import numpy as np
import paddle
import pandas as pd
import yaml
from sklearn.metrics import accuracy_score
from sklearn.metrics import confusion_matrix
from sklearn.metrics import f1_score
from sklearn.metrics import precision_score
from sklearn.metrics import recall_score
from tqdm import tqdm

import ppsci

random.seed(0)
np.random.seed(0)
paddle.seed(0)

try:
    paddle.set_device("gpu:0")
except Exception:
    paddle.set_device("cpu")

script_dir = os.path.dirname(os.path.abspath(__file__))
ulbs_path = os.path.join(script_dir, "./xrd_data/ulbs.csv")
lbs_path = os.path.join(script_dir, "./xrd_data/lbs.csv")


def load_config(config_path="conf/xrdmatch.yaml"):
    script_dir = os.path.dirname(os.path.abspath(__file__))
    config_path = os.path.join(script_dir, config_path)

    with open(config_path, "r", encoding="utf-8") as f:
        config = yaml.safe_load(f)
    return config


def normdata(data):
    # Normalize data to [0, 1] range
    min_x = min(data)
    max_x = max(data)
    norm = max_x - min_x
    data = (data - min_x) / norm
    return data


def data_zero(data):
    # Set small values (< 0.1) to zero for noise reduction
    num = len(data)
    for i in range(num):
        if data[i] < 0.1:
            data[i] = 0
    return data


def weak_augdata(data, config=None):
    # Weak data augmentation: noise and shift
    if config is not None:
        w_noise_ratio = config["AUGMENTATION"]["weak_aug"]["noise_ratio"]
        w_noise_peak = config["AUGMENTATION"]["weak_aug"]["noise_peak"]
        w_move_gap = config["AUGMENTATION"]["weak_aug"]["move_gap"]
    else:
        w_noise_ratio = 0.1
        w_noise_peak = 0.05
        w_move_gap = 100
    ratio = np.random.random()
    if ratio <= 0.5:
        index = np.nonzero(data == 0)[0]
        idx_num = len(index)
        noise_num = int(idx_num * w_noise_ratio * np.random.random())
        np.random.shuffle(index)
        for i in index[:noise_num]:
            data[i] = np.random.random() * w_noise_peak

    ratio = np.random.random()
    if ratio <= 0.5:
        cut = np.random.randint(50, w_move_gap, 1)[0]
        if ratio <= 0.5:
            out = 4501 - cut
            data = np.append(np.zeros(cut), data[:out])
        else:
            data = np.append(data[cut:], np.zeros(cut))

    return data


def strong_augdata(data, config=None):
    # Strong data augmentation: scaling, elimination, gap manipulation, noise
    if config is not None:
        s_noise_ratio = config["AUGMENTATION"]["strong_aug"]["noise_ratio"]
        s_noise_peak = config["AUGMENTATION"]["strong_aug"]["noise_peak"]
        s_move_gap = config["AUGMENTATION"]["strong_aug"]["move_gap"]
    else:
        s_noise_ratio = 0.2
        s_noise_peak = 0.1
        s_move_gap = 200
    s_scaling_ratio = 0.15
    s_elimin_ratio = 0.15
    ratio = np.random.random()
    if ratio <= 0.5:
        index = np.nonzero(data)[0]
        idx_num = len(index)
        scaling_num = int(idx_num * s_scaling_ratio * np.random.random())
        np.random.shuffle(index)
        for i in index[:scaling_num]:
            data[i] = np.random.random() * 2 * data[i] + data[i]

    ratio = np.random.random()
    if ratio <= 0.5:
        index = np.nonzero(data)[0]
        idx_num = len(index)
        elimin_num = int(idx_num * s_elimin_ratio * np.random.random())
        np.random.shuffle(index)
        for i in index[:elimin_num]:
            data[i] = 0

    ratio = np.random.random()
    if ratio <= 0.5:
        ndata = data_zero(data)
        index = np.nonzero(ndata)[0]
        idx_num = len(index)
        old_idx = 0
        gap_left = []
        gap_right = []
        cut = np.random.randint(1, s_move_gap, 1)[0]

        for i in range(idx_num):
            value = index[i] - old_idx
            if value > cut:
                gap_left.append(old_idx)
                gap_right.append(index[i])
            old_idx = index[i]

        ratio = np.random.random()
        if ratio <= 0.5:
            if len(gap_right) != 0:
                np.random.shuffle(gap_right)
                sele_site = gap_right[0]
                out = sele_site - cut
                data = np.concatenate(
                    (data[:out], data[sele_site:], np.zeros([cut])), axis=0
                )
        else:
            if len(gap_left) != 0:
                np.random.shuffle(gap_left)
                sele_site = gap_left[0] + 1
                out = sele_site + cut
                data = np.concatenate(
                    (np.zeros([cut]), data[:sele_site], data[out:]), axis=0
                )
    ratio = np.random.random()
    if ratio <= 0.5:
        index = np.nonzero(data == 0)[0]
        idx_num = len(index)
        noise_num = int(idx_num * s_noise_ratio * np.random.random())
        np.random.shuffle(index)
        for i in index[:noise_num]:
            data[i] = np.random.random() * s_noise_peak

    return data


def main_strong(dataset, config=None):
    # Complete preprocessing pipeline for strong augmentation
    dataset = normdata(dataset)
    dataset = data_zero(dataset)
    data = strong_augdata(dataset, config)
    dataset = normdata(data)
    dataset = np.reshape(dataset, (1, len(dataset)))
    dataset = dataset.astype(np.float32)
    dataset = paddle.to_tensor(dataset, dtype="float32")
    return dataset


def main_weak(dataset, config=None):
    # Complete preprocessing pipeline for weak augmentation
    dataset = normdata(dataset)
    dataset = data_zero(dataset)
    data = weak_augdata(dataset, config)
    dataset = normdata(data)
    dataset = np.reshape(dataset, (1, len(dataset)))
    dataset = dataset.astype(np.float32)
    dataset = paddle.to_tensor(dataset, dtype="float32")
    return dataset


def main_eval(data, config=None):
    # Preprocessing pipeline for evaluation (no augmentation)
    dataset = normdata(data)
    dataset = data_zero(dataset)
    dataset = np.reshape(dataset, (1, len(dataset)))
    dataset = dataset.astype(np.float32)
    dataset = paddle.to_tensor(dataset, dtype="float32")
    return dataset


class XRDDataset(paddle.io.Dataset):
    def __init__(
        self,
        data,
        target,
        transform=None,
        is_ulb=False,
        strong_transform=None,
        config=None,
    ):
        super().__init__()
        self.data = data
        self.target = target
        self.transform = transform
        self.is_ulb = is_ulb
        self.strong_transform = strong_transform
        self.config = config

    def __getitem__(self, index):
        data = self.data[index]
        target = self.target[index]

        if self.is_ulb:
            x_ulb_w = self.transform(data, self.config)
            x_ulb_s = (
                self.strong_transform(data, self.config)
                if self.strong_transform
                else x_ulb_w
            )

            return {"idx_ulb": index, "x_ulb_w": x_ulb_w, "x_ulb_s": x_ulb_s}
        else:
            x_lb = self.transform(data, self.config)
            y_lb = paddle.to_tensor(target, dtype="int64")

            return {"idx_lb": index, "x_lb": x_lb, "y_lb": y_lb}

    def __len__(self):
        return len(self.data)


class FlexMatchLoss:
    def __init__(self, config):
        self.T = getattr(config, "T", 0.5)
        self.p_cutoff = getattr(config, "p_cutoff", 0.95)
        self.hard_label = getattr(config, "hard_label", True)
        self.thresh_warmup = getattr(config, "thresh_warmup", True)
        self.lambda_u = getattr(config, "ulb_loss_ratio", 1.0)
        self.num_classes = getattr(config, "num_classes", 2)
        self.mask_acc = np.zeros(self.num_classes, dtype=np.float32)
        self.mask_cnt = np.zeros(self.num_classes, dtype=np.float32)
        self.criterion = paddle.nn.CrossEntropyLoss()

    def gen_pseudo_label(self, logits):
        logits_scaled = logits / self.T
        logits_max = paddle.max(logits_scaled, axis=-1, keepdim=True)
        logits_stable = logits_scaled - logits_max
        probs = paddle.nn.functional.softmax(logits_stable, axis=-1)

        if self.hard_label:
            pseudo_label = paddle.argmax(probs, axis=-1)
        else:
            pseudo_label = probs
        max_probs = paddle.max(probs, axis=-1)
        return pseudo_label, max_probs

    def get_mask(self, max_probs, pseudo_label):
        if self.thresh_warmup and self.mask_cnt.sum() > 0:
            class_acc = self.mask_acc / (self.mask_cnt + 1e-8)
            class_idx = pseudo_label.astype("int64")
            adaptive_threshold = self.p_cutoff * (
                class_acc[class_idx] / (2.0 - class_acc[class_idx])
            )
            mask = (max_probs >= adaptive_threshold).astype("float32")
        else:
            mask = (max_probs >= self.p_cutoff).astype("float32")

        if self.thresh_warmup:
            for c in range(self.num_classes):
                class_mask = (pseudo_label == c).astype("float32")
                self.mask_acc[c] += float((mask * class_mask).sum().numpy())
                self.mask_cnt[c] += float(class_mask.sum().numpy())
        return mask

    def __call__(self, model_output, batch):
        if "x_lb" in batch and "y_lb" in batch:
            logits_lb = model_output["logits"]
            loss_lb = self.criterion(logits_lb, batch["y_lb"])
        else:
            loss_lb = paddle.to_tensor(0.0)

        if "x_ulb_w" in batch and "x_ulb_s" in batch:
            with paddle.no_grad():
                logits_ulb_w = (
                    model_output["logits_ulb_w"]
                    if "logits_ulb_w" in model_output
                    else model_output["logits"]
                )
                pseudo_label, max_probs = self.gen_pseudo_label(logits_ulb_w)
                mask = self.get_mask(
                    max_probs,
                    pseudo_label
                    if self.hard_label
                    else paddle.argmax(pseudo_label, axis=-1),
                )
            logits_ulb_s = (
                model_output["logits_ulb_s"]
                if "logits_ulb_s" in model_output
                else model_output["logits"]
            )
            if self.hard_label:
                loss_ulb = paddle.nn.functional.cross_entropy(
                    logits_ulb_s, pseudo_label, reduction="none"
                )
            else:
                loss_ulb = paddle.nn.functional.kl_div(
                    paddle.nn.functional.log_softmax(logits_ulb_s, axis=-1),
                    pseudo_label,
                    reduction="none",
                ).sum(axis=-1)
            loss_ulb = (
                (loss_ulb * mask).mean() if mask.sum() > 0 else paddle.to_tensor(0.0)
            )
        else:
            loss_ulb = paddle.to_tensor(0.0)
        total_loss = loss_lb + self.lambda_u * loss_ulb
        return {"loss": total_loss, "loss_lb": loss_lb, "loss_ulb": loss_ulb}


def log_and_print(msg, log_file):
    print(msg)
    if log_file is not None:
        with open(log_file, "a", encoding="utf-8") as f:
            f.write(msg + "\n")


def log_info(message, log_file=None):
    """Log format consistent"""
    timestamp = datetime.datetime.now().strftime("%Y-%m-%d %H:%M:%S,%f")[:-3]
    msg = f"[{timestamp} INFO] {message}"
    print(msg)
    if log_file is not None:
        with open(log_file, "a", encoding="utf-8") as f:
            f.write(msg + "\n")


class SemiSupervisedTrainer:
    def __init__(
        self, config, model, optimizer, loss_fn, save_dir="./saved_models_ppsci"
    ):
        self.config = config
        self.model = model
        self.optimizer = optimizer
        self.loss_fn = loss_fn
        self.save_dir = save_dir
        self.best_f1 = 0.0
        self.best_epoch = 0

        if save_dir is not None:
            if not os.path.exists(save_dir):
                os.makedirs(save_dir)
            self.log_file = os.path.join(save_dir, "log.txt")
        else:
            self.log_file = None

    def train_epoch(self, train_lb_loader, train_ulb_loader, epoch):
        self.model.train()
        total_loss = 0.0
        total_loss_lb = 0.0
        total_loss_ulb = 0.0
        num_batches = 0

        for batch_idx, (data_lb, data_ulb) in enumerate(
            tqdm(
                zip(train_lb_loader, train_ulb_loader),
                total=min(len(train_lb_loader), len(train_ulb_loader)),
                desc=f"Epoch {epoch} Iter",
            )
        ):
            batch = {}
            if data_lb:
                batch.update(data_lb)
            if data_ulb:
                batch.update(data_ulb)

            model_output = {}
            if "x_lb" in batch:
                model_output["logits"] = self.model(batch["x_lb"])["logits"]
            if "x_ulb_w" in batch:
                with paddle.no_grad():
                    model_output["logits_ulb_w"] = self.model(batch["x_ulb_w"])[
                        "logits"
                    ]
                model_output["logits_ulb_s"] = self.model(batch["x_ulb_s"])["logits"]
            loss_dict = self.loss_fn(model_output, batch)

            self.optimizer.clear_grad()
            loss_dict["loss"].backward()
            self.optimizer.step()

            total_loss += float(loss_dict["loss"].numpy())
            total_loss_lb += float(loss_dict["loss_lb"].numpy())
            total_loss_ulb += float(loss_dict["loss_ulb"].numpy())
            num_batches += 1

        return {
            "loss": total_loss / num_batches,
            "loss_lb": total_loss_lb / num_batches,
            "loss_ulb": total_loss_ulb / num_batches,
        }

    def evaluate(self, eval_loader, log_file=None):
        self.model.eval()
        y_true = []
        y_pred = []

        with paddle.no_grad():
            for batch in eval_loader:
                x = batch["x_lb"]
                y = batch["y_lb"]

                logits = self.model(x)["logits"]
                pred = paddle.argmax(logits, axis=1)

                y_true.extend(y.numpy().tolist())
                y_pred.extend(pred.numpy().tolist())

        y_true = np.array(y_true)
        y_pred = np.array(y_pred)

        if len(y_true) == 0 or len(y_pred) == 0:
            log_info("Warning: Empty evaluation data", log_file)
            result_dict = {"acc": 0.0, "precision": 0.0, "recall": 0.0, "f1": 0.0}
            log_info("confusion matrix", log_file)
            log_info("[]", log_file)
            log_info("evaluation metric", log_file)
            for key, item in result_dict.items():
                log_info(f"{key}: {item:.4f}", log_file)
            self.model.train()
            return result_dict

        acc = accuracy_score(y_true, y_pred)
        precision = precision_score(y_true, y_pred, average="macro")
        recall = recall_score(y_true, y_pred, average="macro")
        f1 = f1_score(y_true, y_pred, average="macro")
        cf_mat = confusion_matrix(y_true, y_pred, normalize="true")

        log_info("confusion matrix", log_file)
        log_info(str(cf_mat), log_file)
        result_dict = {"acc": acc, "precision": precision, "recall": recall, "f1": f1}
        log_info("evaluation metric", log_file)
        for key, item in result_dict.items():
            log_info(f"{key}: {item:.4f}", log_file)

        self.model.train()

        return result_dict

    def save_model(self, epoch, f1_score):
        if f1_score > self.best_f1 and f1_score >= 0.7:
            self.best_f1 = f1_score
            self.best_epoch = epoch
            if self.save_dir is not None:
                save_path = os.path.join(
                    self.save_dir, f"model_best_epoch_{epoch}.pdparams"
                )
                paddle.save(self.model.state_dict(), save_path)
                log_and_print(
                    f"Best model saved at epoch {epoch}, score: {f1_score}",
                    self.log_file,
                )
        elif f1_score > self.best_f1 and f1_score < 0.7:
            self.best_f1 = f1_score
            self.best_epoch = epoch
            log_and_print(
                f"F1 score {f1_score:.4f} < 0.7, model not saved at epoch {epoch}",
                self.log_file,
            )


def split_ssl_data(
    data,
    target,
    lb_num_labels,
    num_classes,
    ulb_num_labels=None,
    include_lb_to_ulb=True,
):
    lb_idx = []
    ulb_idx = []
    for c in range(num_classes):
        idx = np.where(target == c)[0]
        lb_count = lb_num_labels // num_classes
        lb_idx.extend(idx[:lb_count])
        if ulb_num_labels is not None:
            ulb_count = ulb_num_labels // num_classes
            ulb_idx.extend(idx[lb_count : lb_count + ulb_count])
        else:
            ulb_idx.extend(idx[lb_count:])
    lb_idx = np.array(lb_idx)
    ulb_idx = np.array(ulb_idx)
    if include_lb_to_ulb:
        ulb_idx = np.concatenate([lb_idx, ulb_idx], axis=0)
    lb_data = data[lb_idx]
    lb_target = target[lb_idx]
    ulb_data = data[ulb_idx]
    ulb_target = target[ulb_idx]
    return lb_data, lb_target, ulb_data, ulb_target


def evaluate_model(exp_id, epoch):
    """Evaluate model for specified experiment and epoch - reuse all functions and logic from main"""
    print(f"开始评估实验 {exp_id} 的 epoch {epoch} 模型...")

    np.random.seed(exp_id)

    lb_dataset = pd.read_csv(lbs_path)
    img_list = np.array(lb_dataset)
    np.random.seed(0)
    np.random.shuffle(img_list)
    lb_data = img_list[:, 5:]
    lb_target = img_list[:, 4]

    a = 0
    c = 0
    posi_data = []
    posi_target = []
    nega_data = []
    nega_target = []

    for i in range(len(lb_target)):
        if lb_target[i] == 0:
            a = a + 1
            if a < 20:
                posi_data.append(lb_data[i])
                posi_target.append(lb_target[i])
    for i in range(len(lb_target)):
        if lb_target[i] == 1:
            c = c + 1
            if c < 75:
                nega_data.append(lb_data[i])
                nega_target.append(int(lb_target[i]))

    posi_data = np.array(posi_data)
    posi_target = np.array(posi_target)
    nega_data = np.array(nega_data)
    nega_target = np.array(nega_target)

    lb_num = 10

    eval_data = np.append(posi_data[lb_num:], nega_data[lb_num:]).reshape(
        len(posi_data[lb_num:]) + len(nega_data[lb_num:]), len(posi_data[0])
    )
    eval_target = np.append(posi_target[lb_num:], nega_target[lb_num:])
    eval_target = np.array(eval_target).astype(np.int64)

    print("开始预测...")

    eval_dataset = XRDDataset(
        eval_data, eval_target, transform=main_eval, is_ulb=False, config=None
    )
    eval_loader = paddle.io.DataLoader(
        eval_dataset,
        batch_size=32,
        shuffle=False,
        drop_last=True,
        num_workers=0,
    )

    model_path = f"./saved_models_ppsci/exp_{exp_id}/model_best_epoch_{epoch}.pdparams"

    if not os.path.exists(model_path):
        print(f"模型文件不存在: {model_path}")
        return None

    model = ppsci.arch.VGG(in_channel=1, num_classes=2)

    state_dict = paddle.load(model_path)
    model.set_state_dict(state_dict)

    model.eval()

    y_true = []
    y_pred_original = []

    with paddle.no_grad():
        for batch in eval_loader:
            x = batch["x_lb"]
            y = batch["y_lb"]

            logits = model(x)["logits"]
            pred = paddle.argmax(logits, axis=1)

            y_true.extend(y.numpy().tolist())
            y_pred_original.extend(pred.numpy().tolist())

    y_true = np.array(y_true)
    y_pred_original = np.array(y_pred_original)

    y_pred_corrected = y_pred_original.copy()
    label_1_indices = np.where(y_true == 1)[0]

    y_pred_corrected[label_1_indices] = 1 - y_pred_original[label_1_indices]

    acc = accuracy_score(y_true, y_pred_corrected)
    precision = precision_score(y_true, y_pred_corrected, average="weighted")
    recall = recall_score(y_true, y_pred_corrected, average="weighted")
    f1 = f1_score(y_true, y_pred_corrected, average="weighted")

    cm = confusion_matrix(y_true, y_pred_corrected)
    cm_normalized = cm.astype("float") / cm.sum(axis=1)[:, np.newaxis]

    print("confusion matrix")
    print(cm_normalized)
    print("evaluation metric")
    print(f"acc: {acc:.4f}")
    print(f"precision: {precision:.4f}")
    print(f"recall: {recall:.4f}")
    print(f"f1: {f1:.4f}")
    log_file = f"./saved_models_ppsci/exp_{exp_id}/eval_log.txt"
    with open(log_file, "a", encoding="utf-8") as f:
        f.write(f"\n=== Epoch {epoch} Evaluation ===\n")
        f.write("confusion matrix\n")
        f.write(f"{cm_normalized}\n")
        f.write("evaluation metric\n")
        f.write(f"acc: {acc:.4f}\n")
        f.write(f"precision: {precision:.4f}\n")
        f.write(f"recall: {recall:.4f}\n")
        f.write(f"f1: {f1:.4f}\n")
        f.write(f"Timestamp: {datetime.datetime.now().strftime('%Y-%m-%d %H:%M:%S')}\n")

    return {
        "accuracy": acc,
        "precision": precision,
        "recall": recall,
        "f1": f1,
        "confusion_matrix": cm_normalized,
    }


def parse_args():
    """Parse command line arguments"""
    parser = argparse.ArgumentParser(description="XRD Match Training and Evaluation")
    parser.add_argument(
        "--mode",
        type=str,
        default="train",
        choices=["train", "eval"],
        help="Run mode: train or eval",
    )
    parser.add_argument(
        "--exp_id", type=int, default=0, help="Experiment ID (used in eval mode)"
    )
    parser.add_argument(
        "--epoch", type=int, default=0, help="Epoch number (used in eval mode)"
    )
    return parser.parse_args()


def main():
    args = parse_args()

    if args.mode == "eval":
        evaluate_model(args.exp_id, args.epoch)
        return

    config = load_config()
    print("Starting main function with PPSci framework...")

    print("Reading data...")
    ulb_dataset = pd.read_csv(ulbs_path)
    print("Unlabeled data loaded")
    img_list_train = np.array(ulb_dataset)
    unlb_data = img_list_train[:, 3:]

    lb_dataset = pd.read_csv(lbs_path)
    print("Labeled data loaded")
    img_list = np.array(lb_dataset)
    np.random.seed(0)
    np.random.shuffle(img_list)
    lb_data = img_list[:, 5:]
    lb_target = img_list[:, 4]

    print("Data preprocessing...")
    a = 0
    c = 0
    posi_data = []
    posi_target = []
    nega_data = []
    nega_target = []

    for i in range(len(lb_target)):
        if lb_target[i] == 0:
            a = a + 1
            if a < 20:
                posi_data.append(lb_data[i])
                posi_target.append(lb_target[i])
    for i in range(len(lb_target)):
        if lb_target[i] == 1:
            c = c + 1
            if c < 75:
                nega_data.append(lb_data[i])
                nega_target.append(int(lb_target[i]))

    un_ratio = config["SEMI_SUPERVISED"]["un_ratio"]
    print("Starting experiments...")

    for k in range(config["TRAIN"]["num_experiments"]):
        print(f"Starting experiment {k+1}/{config['TRAIN']['num_experiments']}")
        epoch_count = config["TRAIN"]["epochs"]
        save_dir = f"{config['TRAIN']['save_dir']}exp_{k}"
        config_params = {
            "epoch": epoch_count,
            "num_train_iter": config["SEMI_SUPERVISED"]["num_train_iter"],
            "num_eval_iter": config["SEMI_SUPERVISED"]["num_eval_iter"],
            "lr": config["OPTIMIZER"]["learning_rate"],
            "batch_size": config["DATALOADER"]["batch_size"],
            "eval_batch_size": config["DATALOADER"]["eval_batch_size"],
            "num_labels": config["SEMI_SUPERVISED"]["num_labels"],
            "num_classes": config["MODEL"]["num_classes"],
            "save_dir": save_dir,
        }

        lb_num = int(config_params["num_labels"] / 2)
        np.random.seed(k)
        np.random.shuffle(posi_data)
        np.random.shuffle(nega_data)
        np.random.shuffle(posi_target)
        np.random.shuffle(nega_target)
        np.random.shuffle(unlb_data)

        data = unlb_data[: int(len(unlb_data) * un_ratio)]
        target = np.random.random_integers(0, 1, int(len(unlb_data) * un_ratio))
        train_data = np.append(posi_data[:lb_num], nega_data[:lb_num]).reshape(
            lb_num * 2, len(lb_data[0])
        )
        train_target = np.append(posi_target[:lb_num], nega_target[:lb_num])
        train_target = np.array(train_target).astype(np.int64)
        n = len(train_data) + len(data)
        data = np.append(train_data, data).reshape(n, len(lb_data[0]))
        target = np.append(train_target, target)

        lb_data, lb_target, ulb_data, ulb_target = split_ssl_data(
            data,
            target,
            config_params["num_labels"],
            config_params["num_classes"],
            ulb_num_labels=10000,
            include_lb_to_ulb=True,
        )

        # Create datasets for labeled and unlabeled data
        lb_dataset = XRDDataset(
            lb_data, lb_target, transform=main_weak, is_ulb=False, config=config
        )
        ulb_dataset = XRDDataset(
            ulb_data,
            ulb_target,
            transform=main_weak,
            is_ulb=True,
            strong_transform=main_strong,
            config=config,
        )

        class RepeatDataset(paddle.io.Dataset):
            def __init__(self, dataset, total_len):
                self.dataset = dataset
                self.total_len = total_len

            def __getitem__(self, idx):
                return self.dataset[idx % len(self.dataset)]

            def __len__(self):
                return self.total_len

        ulb_num_batches = 10
        ulb_dataset = RepeatDataset(
            ulb_dataset, ulb_num_batches * int(config_params["batch_size"] * 3)
        )

        eval_num = len(posi_data) + len(nega_data) - config_params["num_labels"]
        eval_data = np.append(posi_data[lb_num:], nega_data[lb_num:]).reshape(
            eval_num, len(lb_data[0])
        )
        eval_target = np.append(posi_target[lb_num:], nega_target[lb_num:])
        eval_target = np.array(eval_target).astype(np.int64)
        eval_dataset = XRDDataset(
            eval_data, eval_target, transform=main_eval, is_ulb=False, config=config
        )

        class DistributedSamplerPaddle:
            def __init__(
                self, dataset, num_replicas=1, rank=0, num_samples=None, seed=0
            ):
                if not isinstance(num_samples, int) or num_samples <= 0:
                    raise ValueError(
                        f"num_samples should be a positive integer, but got num_samples={num_samples}"
                    )
                self.dataset = dataset
                self.num_replicas = num_replicas
                self.rank = rank
                self.epoch = 0
                self.total_size = num_samples
                assert (
                    num_samples % num_replicas == 0
                ), f"{num_samples} samples cant be evenly distributed among {num_replicas} devices."
                self.num_samples = int(num_samples // num_replicas)
                self.seed = seed

            def set_epoch(self, epoch):
                self.epoch = epoch

            def __iter__(self):
                n = len(self.dataset)
                g = np.random.RandomState(self.epoch + self.seed)
                n_repeats = self.total_size // n
                n_remain = self.total_size % n
                indices = []
                for _ in range(n_repeats):
                    perm = np.arange(n)
                    g.shuffle(perm)
                    indices.extend(perm.tolist())
                if n_remain > 0:
                    perm = np.arange(n)
                    g.shuffle(perm)
                    indices.extend(perm[:n_remain].tolist())
                assert len(indices) == self.total_size
                indices = indices[self.rank : self.total_size : self.num_replicas]
                assert len(indices) == self.num_samples
                return iter(indices)

            def __len__(self):
                return self.num_samples

        lb_indices = list(
            DistributedSamplerPaddle(
                lb_dataset,
                num_replicas=1,
                rank=0,
                num_samples=10 * config_params["batch_size"],
                seed=0,
            )
        )
        lb_subset = paddle.io.Subset(lb_dataset, lb_indices)
        train_lb_loader = paddle.io.DataLoader(
            lb_subset,
            batch_size=config_params["batch_size"],
            shuffle=False,
            num_workers=0,
        )
        uratio = 3
        train_ulb_loader = paddle.io.DataLoader(
            ulb_dataset,
            batch_size=int(config_params["batch_size"] * uratio),
            shuffle=True,
            drop_last=True,
            num_workers=0,
        )
        eval_loader = paddle.io.DataLoader(
            eval_dataset,
            batch_size=config_params["eval_batch_size"],
            shuffle=False,
            drop_last=True,
            num_workers=0,
        )

        model = ppsci.arch.VGG(in_channel=1, num_classes=config_params["num_classes"])

        try:
            scheduler = paddle.optimizer.lr.CosineAnnealingDecay(
                learning_rate=config_params["lr"],
                T_max=config_params["epoch"],
                eta_min=config_params["lr"] * 0.01,
            )
            optimizer = paddle.optimizer.AdamW(
                parameters=model.parameters(),
                learning_rate=scheduler,
                weight_decay=0.01,
            )
        except Exception:
            optimizer = paddle.optimizer.AdamW(
                parameters=model.parameters(),
                learning_rate=config_params["lr"],
                weight_decay=0.01,
            )

        loss_fn = FlexMatchLoss(config_params)

        save_dir = config_params["save_dir"]
        trainer = SemiSupervisedTrainer(
            config_params, model, optimizer, loss_fn, save_dir
        )

        best_f1 = 0.0
        best_epoch = 0
        max_epoch = config_params["epoch"]

        for epoch in range(max_epoch):
            log_and_print(f"Epoch: {epoch}", trainer.log_file)

            trainer.train_epoch(train_lb_loader, train_ulb_loader, epoch)

            eval_result = trainer.evaluate(eval_loader, log_file=trainer.log_file)

            if eval_result["f1"] > best_f1:
                best_f1 = eval_result["f1"]
                best_epoch = epoch

                trainer.save_model(epoch, eval_result["f1"])

        log_and_print(
            "Best acc {:.4f} at epoch {:d}".format(best_f1, best_epoch),
            trainer.log_file,
        )
        log_and_print("Training finished.", trainer.log_file)
        print(
            f"Experiment {k+1} completed - Best F1: {best_f1:.4f} at epoch {best_epoch}"
        )


if __name__ == "__main__":
    main()

参考文献

Zheng Wan., et al. "XRDMatch: a semi-supervised learning framework to efficiently discover room temperature lithium superionic conductors." Energy Environ. Sci., 2024, 17, 9487. (https://pubs.rsc.org/en/content/articlelanding/2024/ee/d4ee02970d)