開始
│
├─ 初始化設(shè)置（隨機(jī)種子、目錄創(chuàng)建）
├─ 自定義層定義（SEBlock1, NeuralODEBlock1, EnhancedGatedAttention1等）
├─ 混合模型構(gòu)建（build_hybrid_model）
│   ├─ 輸入層
│   ├─ 共享卷積層
│   ├─ 三條并行路徑：
│   │   ├─ 時(shí)域路徑（卷積+注意力+神經(jīng)ODE）
│   │   ├─ 頻域路徑（傅里葉神經(jīng)算子+注意力）
│   │   └─ LSTM路徑（LSTM+SE塊）
│   ├─ 多路徑特征融合（注意力加權(quán)）
│   └─ 輸出層（全連接+分類）
├─ 數(shù)據(jù)加載與預(yù)處理（load_surf_dataset）
│   ├─ 讀取.mat/.csv文件
│   ├─ 信號(hào)長(zhǎng)度標(biāo)準(zhǔn)化
│   └─ 標(biāo)簽編碼
├─ 模型編譯與訓(xùn)練
│   ├─ 自定義F1評(píng)估指標(biāo)
│   ├─ 類別權(quán)重平衡
│   └─ 模型訓(xùn)練
├─ 性能評(píng)估與可視化
│   ├─ 訓(xùn)練指標(biāo)曲線
│   ├─ 測(cè)試集評(píng)估
│   ├─ 噪聲魯棒性測(cè)試
│   ├─ 特征空間可視化（UMAP/t-SNE）
│   ├─ 混淆矩陣/ROC曲線
│   └─ 層激活可視化
└─ 高級(jí)信號(hào)分析
    ├─ 時(shí)域/頻域分析
    ├─ 時(shí)頻分析（STFT/小波）
    └─ 特征分布可視化
結(jié)束

# 導(dǎo)入必要的庫(kù)
import os  # 提供操作系統(tǒng)相關(guān)功能
import numpy as np  # 科學(xué)計(jì)算庫(kù)
import tensorflow as tf  # 深度學(xué)習(xí)框架
from tensorflow.keras.layers import (  # Keras層組件
    Input, Conv1D, BatchNormalization, Dense, Dropout, LSTM, Concatenate, Add,
    LayerNormalization, Activation, GlobalAveragePooling1D, Multiply, Reshape, Lambda)
from tensorflow.keras.models import Model  # 模型構(gòu)建
from tensorflow.keras.utils import to_categorical  # 類別編碼
from sklearn.preprocessing import LabelEncoder  # 標(biāo)簽編碼
from sklearn.utils import class_weight  # 類別權(quán)重計(jì)算
import matplotlib.pyplot as plt  # 繪圖庫(kù)
import scipy.io  # MATLAB文件處理
import pandas as pd  # 數(shù)據(jù)處理
import pickle  # 數(shù)據(jù)序列化
from scipy.signal import stft, hilbert  # 信號(hào)處理
import seaborn as sns  # 統(tǒng)計(jì)可視化
import umap  # 降維可視化
from sklearn.manifold import TSNE  # t-SNE降維
from sklearn.metrics import (  # 評(píng)估指標(biāo)
    accuracy_score, precision_score, recall_score, f1_score, roc_auc_score,
    confusion_matrix, ConfusionMatrixDisplay, roc_curve, auc)


# 設(shè)置隨機(jī)種子確保結(jié)果可重現(xiàn)
seed_value = 1234
np.random.seed(seed_value)
tf.manual_seed(seed_value)


# 創(chuàng)建報(bào)告目錄用于保存結(jié)果
os.makedirs("Report", exist_ok=True)


# 定義信號(hào)維度參數(shù)
n_u, n_y = 2, 2  # 輸入輸出通道數(shù)
seq_len = 1024  # 信號(hào)長(zhǎng)度
input_shape = (seq_len, 1)  # 輸入形狀
num_classes = 3  # 故障類別數(shù)


### 自定義神經(jīng)網(wǎng)絡(luò)層實(shí)現(xiàn) ###


class SEBlock1(Layer):
    """擠壓激勵(lì)注意力模塊 (Squeeze-and-Excitation Block)"""
    def __init__(self, reduction_ratio=8, **kwargs):
        """
        初始化SE塊
        :param reduction_ratio: 通道壓縮比例
        """
        super().__init__(**kwargs)
        self.reduction_ratio = reduction_ratio


    def build(self, input_shape):
        """構(gòu)建層權(quán)重"""
        channels = input_shape[-1]  # 獲取輸入通道數(shù)
        # 使用1x1卷積替代全連接層加速計(jì)算
        self.conv1 = Conv1D(channels//self.reduction_ratio, 1, activation='relu')  # 降維卷積
        self.conv2 = Conv1D(channels, 1, activation='sigmoid')  # 重建卷積
        super().build(input_shape)


    def call(self, inputs):
        """前向傳播邏輯"""
        # 全局平均池化替代全連接層
        se = tf.reduce_mean(inputs, axis=1, keepdims=True)  # 空間維度壓縮
        se = self.conv1(se)  # 通道壓縮
        se = self.conv2(se)  # 通道重建
        return Multiply()([inputs, se])  # 通道加權(quán)


    def compute_output_shape(self, input_shape):
        """輸出形狀計(jì)算"""
        return input_shape




class NeuralODEBlock1(Layer):
    """神經(jīng)常微分方程塊 (Neural Ordinary Differential Equations Block)"""
    def __init__(self, units, time_steps=10, **kwargs):
        """
        初始化神經(jīng)ODE塊
        :param units: 隱藏單元數(shù)
        :param time_steps: 時(shí)間步長(zhǎng)
        """
        super().__init__(**kwargs)
        self.units = units
        self.time_steps = time_steps
        self.dense1 = Dense(units, activation='tanh')  # 非線性變換層
        self.dense2 = Dense(units)  # 導(dǎo)數(shù)計(jì)算層


    def call(self, x):
        """前向傳播實(shí)現(xiàn)歐拉積分"""
        outputs = []  # 存儲(chǔ)各時(shí)間步輸出
        h = x  # 初始狀態(tài)


        # 通過(guò)歐拉方法模擬ODE
        for t in range(self.time_steps):
            dx = self.dense2(self.dense1(h))  # 計(jì)算導(dǎo)數(shù)
            h = h + dx  # 狀態(tài)更新
            outputs.append(h)  # 保存當(dāng)前狀態(tài)


        # 拼接所有時(shí)間步輸出
        stacked = tf.concat(outputs, axis=1)
        return stacked


    def compute_output_shape(self, input_shape):
        """輸出形狀計(jì)算"""
        return (input_shape[0], self.time_steps, self.units)




class EnhancedGatedAttention1(Layer):
    """增強(qiáng)門控注意力機(jī)制 (Enhanced Gated Attention)"""
    def __init__(self, d_model, **kwargs):
        """
        初始化注意力層
        :param d_model: 特征維度
        """
        super().__init__(**kwargs)
        self.d_model = d_model
        # 使用較少注意力頭加速計(jì)算
        self.mha = tf.keras.layers.MultiHeadAttention(
            num_heads=2, key_dim=d_model//2)  # 多頭注意力
        # 使用1D卷積替代全連接加速門控計(jì)算
        self.gate = Conv1D(1, kernel_size=1, activation='sigmoid')  # 門控生成
        # 使用批歸一化替代層歸一化加速訓(xùn)練
        self.norm = BatchNormalization()  # 歸一化層


    def call(self, x):
        """前向傳播邏輯"""
        attn = self.mha(x, x)  # 自注意力計(jì)算
        gate = self.gate(x)  # 門控信號(hào)生成
        # 殘差連接+門控注意力
        return self.norm(x + attn * gate)  # 特征更新




class VanillaSelfAttention(Layer):
    """標(biāo)準(zhǔn)自注意力機(jī)制 (Vanilla Self-Attention)"""
    def __init__(self, d_model, **kwargs):
        """初始化標(biāo)準(zhǔn)注意力層"""
        super().__init__(**kwargs)
        self.d_model = d_model
        # 使用與增強(qiáng)門控注意力相同的配置
        self.mha = tf.keras.layers.MultiHeadAttention(
            num_heads=2, key_dim=d_model//2)
        self.norm = BatchNormalization()


    def call(self, x):
        """前向傳播邏輯"""
        attn = self.mha(x, x)  # 自注意力計(jì)算
        return self.norm(x + attn)  # 殘差連接




class FourierNeuralOperator1(Layer):
    """傅里葉神經(jīng)算子 (Fourier Neural Operator)"""
    def __init__(self, modes, filters, **kwargs):
        """
        初始化FNO層
        :param modes: 保留的傅里葉模式數(shù)
        :param filters: 濾波器數(shù)量
        """
        super().__init__(**kwargs)
        self.modes = modes
        self.filters = filters
        # 使用更窄的全連接層加速計(jì)算
        self.fft_dense = Dense(filters//4, activation='gelu')  # 傅里葉域變換
        self.ifft_dense = Dense(filters//2)  # 逆傅里葉域變換


    def call(self, x):
        """前向傳播邏輯"""
        # 1. 快速傅里葉變換
        x_fft = tf.signal.fft(tf.cast(x, tf.complex64))
        x_fft = tf.math.real(x_fft[..., :self.modes])  # 保留主要模式


        # 2. 傅里葉域特征變換
        x_fft = self.fft_dense(x_fft)
        x_fft = self.ifft_dense(x_fft)


        # 3. 填充并逆變換回時(shí)域
        x_fft = tf.pad(x_fft, [[0,0],[0,0],[0,tf.shape(x)[1]-self.modes]])
        return tf.math.real(tf.signal.ifft(tf.cast(x_fft, tf.complex64)))




### 混合模型構(gòu)建函數(shù) ###


def build_hybrid_model(input_shape, num_classes):
    """
    構(gòu)建三路徑混合故障診斷模型
    :param input_shape: 輸入形狀 (序列長(zhǎng)度, 通道數(shù))
    :param num_classes: 分類類別數(shù)
    :return: 構(gòu)建好的Keras模型
    """
    # 1. 輸入層
    inputs = Input(shape=input_shape)


    # ===== 共享預(yù)處理層 =====
    shared_conv = Conv1D(32, 3, padding='same', name='shared_conv')(inputs)


    # ===== 路徑1: 時(shí)域特征提取 =====
    # 1.1 基礎(chǔ)特征提取
    x_time = Conv1D(64, 3, padding='same', name='time_conv1')(shared_conv)
    x_time = EnhancedGatedAttention1(d_model=64, name='time_attn1')(x_time)
    # 1.2 中間特征保存用于跨路徑連接
    time_mid = Conv1D(64, 3, padding='same', name='time_mid')(x_time)
    # 1.3 神經(jīng)ODE時(shí)間演化
    x_time = GlobalAveragePooling1D(name='time_gap1')(x_time)
    x_time = Reshape((1, 64))(x_time)
    x_time = NeuralODEBlock1(units=64, time_steps=50, name='time_ode')(x_time)
    x_time = GlobalAveragePooling1D(name='time_gap2')(x_time)


    # ===== 路徑2: 頻域特征提取 =====
    # 2.1 傅里葉神經(jīng)算子
    x_freq = FourierNeuralOperator1(modes=16, filters=64, name='fno')(shared_conv)
    # 2.2 跨路徑連接時(shí)域特征
    x_freq = Concatenate(axis=-1, name='freq_concat')([x_freq, time_mid])
    x_freq = Conv1D(64, 1, name='freq_merge')(x_freq)
    # 2.3 頻域注意力增強(qiáng)
    x_freq = EnhancedGatedAttention1(d_model=64, name='freq_attn')(x_freq)
    x_freq = GlobalAveragePooling1D(name='freq_gap')(x_freq)


    # ===== 路徑3: LSTM時(shí)序建模 =====
    # 3.1 LSTM時(shí)序特征提取
    x_lstm = LSTM(64, return_sequences=True, name='lstm1')(shared_conv)
    # 3.2 時(shí)域特征適配
    time_mid_adjusted = Conv1D(64, 1, name='time_mid_adjust')(time_mid)
    # 3.3 頻域特征適配
    x_freq_expanded = Lambda(
        lambda x: tf.repeat(x[0], tf.shape(x[1])[1], axis=1),
        name='freq_expand')([x_freq[:, tf.newaxis, :], x_lstm])
    # 3.4 多源特征融合
    x_lstm = Concatenate(axis=-1, name='lstm_concat')([
        x_lstm, time_mid_adjusted, x_freq_expanded])
    x_lstm = Conv1D(64, 1, name='lstm_merge')(x_lstm)
    # 3.5 通道注意力增強(qiáng)
    x_lstm = SEBlock1(name='lstm_se')(x_lstm)
    x_lstm = GlobalAveragePooling1D(name='lstm_gap')(x_lstm)


    # ===== 多路徑特征融合 =====
    # 4.1 特征拼接
    fused = Concatenate(name='final_concat')([x_time, x_freq, x_lstm])
    # 4.2 注意力加權(quán)融合
    attention_units = fused.shape[-1]  # 自動(dòng)獲取特征維度
    attention_weights = Dense(attention_units, activation='softmax')(fused)
    fused = Multiply(name='attention_scale')([fused, attention_weights])


    # ===== 輸出層 =====
    # 5.1 全連接層
    out = Dense(128, activation='gelu', name='dense1')(fused)
    out = Dropout(0.5, name='dropout1')(out)
    # 5.2 分類輸出層
    out = Dense(num_classes, activation='softmax', name='output')(out)


    return Model(inputs, out)




### 數(shù)據(jù)加載函數(shù) ###


def load_surf_dataset(folder, seq_len=1024):
    """
    加載SURF軸承故障數(shù)據(jù)集
    :param folder: 數(shù)據(jù)文件夾路徑
    :param seq_len: 信號(hào)長(zhǎng)度
    :return: 信號(hào)數(shù)組和標(biāo)簽數(shù)組
    """
    X = []  # 存儲(chǔ)信號(hào)
    y = []  # 存儲(chǔ)標(biāo)簽
    class_names = sorted(os.listdir(folder))  # 獲取故障類別


    # 遍歷每個(gè)故障類別
    for label in class_names:
        class_path = os.path.join(folder, label)
        # 遍歷類別文件夾中的文件
        for fname in os.listdir(class_path):
            file_path = os.path.join(class_path, fname)
            # 處理MATLAB數(shù)據(jù)文件
            if fname.endswith('.mat'):
                mat = scipy.io.loadmat(file_path)
                for key in mat:
                    if not key.startswith("__"):  # 跳過(guò)系統(tǒng)變量
                        signal = mat[key].squeeze()
                        break
            # 處理CSV數(shù)據(jù)文件
            elif fname.endswith('.csv'):
                df = pd.read_csv(file_path, header=None)
                signal = df.values.squeeze()
            else:
                continue


            # 信號(hào)長(zhǎng)度標(biāo)準(zhǔn)化
            if len(signal) >= seq_len:
                signal = signal[:seq_len]  # 截?cái)?            else:
                # 填充不足部分
                signal = np.pad(signal, (0, seq_len - len(signal)))


            X.append(signal)
            y.append(label)


    return np.array(X), np.array(y)




### 自定義評(píng)估指標(biāo) ###


def f1_score(y_true, y_pred):
    """自定義F1分?jǐn)?shù)計(jì)算函數(shù)"""
    y_pred = tf.round(y_pred)  # 預(yù)測(cè)概率轉(zhuǎn)類別
    # 計(jì)算真陽(yáng)性、假陽(yáng)性、假陰性
    tp = tf.reduce_sum(tf.cast(y_true * y_pred, 'float'), axis=0)
    fp = tf.reduce_sum(tf.cast((1 - y_true) * y_pred, 'float'), axis=0)
    fn = tf.reduce_sum(tf.cast(y_true * (1 - y_pred), 'float'), axis=0)


    # 計(jì)算精確率和召回率
    precision = tp / (tp + fp + tf.keras.backend.epsilon())
    recall = tp / (tp + fn + tf.keras.backend.epsilon())


    # 計(jì)算F1分?jǐn)?shù)
    f1 = 2 * precision * recall / (precision + recall + tf.keras.backend.epsilon())
    return tf.reduce_mean(f1)  # 返回宏平均F1




### 主執(zhí)行流程 ###


if __name__ == "__main__":
    # === 數(shù)據(jù)準(zhǔn)備 ===
    # 加載訓(xùn)練集和測(cè)試集
    X_train, y_train = load_surf_dataset("Veriseti_Surf/train", seq_len=seq_len)
    X_test, y_test = load_surf_dataset("Veriseti_Surf/test", seq_len=seq_len)


    # 添加通道維度 (N, seq_len) -> (N, seq_len, 1)
    X_train = X_train[..., np.newaxis]
    X_test = X_test[..., np.newaxis]


    # 標(biāo)簽編碼和one-hot轉(zhuǎn)換
    encoder = LabelEncoder()
    y_train_enc = encoder.fit_transform(y_train)
    y_test_enc = encoder.transform(y_test)
    y_train_cat = to_categorical(y_train_enc, num_classes=num_classes)
    y_test_cat = to_categorical(y_test_enc, num_classes=num_classes)


    # === 模型構(gòu)建與編譯 ===
    model = build_hybrid_model(input_shape=input_shape, num_classes=num_classes)


    # 計(jì)算類別權(quán)重處理不平衡數(shù)據(jù)
    class_weights = class_weight.compute_class_weight(
        class_weight='balanced',
        classes=np.unique(y_train_enc),
        y=y_train_enc
    )
    class_weights_dict = dict(enumerate(class_weights))


    # 模型編譯
    model.compile(
        optimizer=tf.keras.optimizers.Adam(learning_rate=1e-4),
        loss='categorical_crossentropy',
        metrics=[
            'accuracy',
            tf.keras.metrics.Precision(name='precision'),
            tf.keras.metrics.Recall(name='recall'),
            f1_score  # 使用自定義F1指標(biāo)
        ]
    )


    # 打印模型結(jié)構(gòu)
    model.summary()


    # === 模型訓(xùn)練 ===
    history = model.fit(
        X_train, y_train_cat,
        validation_data=(X_test, y_test_cat),
        epochs=50,
        batch_size=256,
        class_weight=class_weights_dict  # 類別權(quán)重
    )


    # === 訓(xùn)練結(jié)果分析 ===
    # 提取訓(xùn)練指標(biāo)
    train_acc = history.history['accuracy']
    train_prec = history.history['precision']
    train_rec = history.history['recall']
    train_f1 = history.history['f1_score']
    train_loss = history.history['loss']


    # 提取驗(yàn)證指標(biāo)
    val_acc = history.history['val_accuracy']
    val_prec = history.history['val_precision']
    val_rec = history.history['val_recall']
    val_f1 = history.history['val_f1_score']
    val_loss = history.history['val_loss']


    # 保存指標(biāo)結(jié)果
    with open("ablation/ab1_acc.pkl", "wb") as f:
        pickle.dump(train_acc, f)
    with open("ablation/ab1_prec.pkl", "wb") as f:
        pickle.dump(train_prec, f)
    with open("ablation/ab1_rec.pkl", "wb") as f:
        pickle.dump(train_rec, f)
    with open("ablation/ab1_f1.pkl", "wb") as f:
        pickle.dump(train_f1, f)


    # === 模型可視化分析 ===
    # 1. 訓(xùn)練過(guò)程指標(biāo)曲線
    plt.figure(figsize=(10, 6))
    epochs = range(1, len(train_acc)+1)
    plt.plot(epochs, train_acc, label='Accuracy')
    plt.plot(epochs, train_prec, label='Precision')
    plt.plot(epochs, train_rec, label='Recall')
    plt.plot(epochs, train_f1, label='F1-Score')
    plt.title('Training Metrics Over Epochs')
    plt.xlabel('Epochs')
    plt.ylabel('Score')
    plt.legend()
    plt.grid(True)
    plt.tight_layout()
    plt.savefig("Report/training_metrics.pdf")
    plt.show()


    # 2. 特征空間可視化 (UMAP)
    feature_extractor = Model(inputs=model.input, outputs=model.layers[-3].output)
    features = feature_extractor.predict(X_test)
    reducer = umap.UMAP(n_neighbors=15, min_dist=0.1, metric='euclidean', random_state=42)
    embedding = reducer.fit_transform(features)


    plt.figure(figsize=(8, 6))
    scatter = plt.scatter(embedding[:, 0], embedding[:, 1], c=y_test_enc, cmap='Set1', alpha=0.8)
    handles, _ = scatter.legend_elements()
    plt.legend(handles=handles, labels=encoder.classes_.tolist())
    plt.title("UMAP Visualization of Feature Space")
    plt.xlabel("UMAP 1")
    plt.ylabel("UMAP 2")
    plt.grid(True)
    plt.tight_layout()
    plt.savefig("Report/feature_space_umap.pdf")
    plt.show()


    # 3. 混淆矩陣
    y_pred = model.predict(X_test)
    y_pred_classes = np.argmax(y_pred, axis=1)
    cm = confusion_matrix(y_test_enc, y_pred_classes)
    disp = ConfusionMatrixDisplay(confusion_matrix=cm, display_labels=encoder.classes_)
    disp.plot(cmap=plt.cm.Blues)
    plt.title("Confusion Matrix")
    plt.savefig("Report/confusion_matrix.pdf")
    plt.show()


    # 4. ROC曲線
    y_test_onehot = to_categorical(y_test_enc, num_classes=num_classes)
    plt.figure(figsize=(8, 6))
    for i in range(num_classes):
        fpr, tpr, _ = roc_curve(y_test_onehot[:, i], y_pred[:, i])
        roc_auc = auc(fpr, tpr)
        plt.plot(fpr, tpr, label=f'{encoder.classes_[i]} (AUC = {roc_auc:.2f})')
    plt.plot([0, 1], [0, 1], 'k--')
    plt.xlabel('False Positive Rate')
    plt.ylabel('True Positive Rate')
    plt.title('ROC Curve for Each Class')
    plt.legend()
    plt.grid(True)
    plt.savefig("Report/roc_curve.pdf")
    plt.show()


    # === 噪聲魯棒性測(cè)試 ===
    def add_gaussian_noise(signal, snr_db):
        """添加高斯白噪聲"""
        signal_power = np.mean(signal ** 2)
        snr_linear = 10 ** (snr_db / 10)
        noise_power = signal_power / snr_linear
        noise = np.random.normal(0, np.sqrt(noise_power), signal.shape)
        return signal + noise


    # 測(cè)試不同信噪比下的性能
    snr_levels = [5, 10, 15, 20]
    X_test_noisy = {}


    # 生成加噪測(cè)試集
    for snr in snr_levels:
        noisy_signals = []
        for signal in X_test.squeeze():
            noisy_signal = add_gaussian_noise(signal, snr)
            noisy_signals.append(noisy_signal)
        X_test_noisy[snr] = np.array(noisy_signals)[..., np.newaxis]


    # 評(píng)估各信噪比下的模型性能
    snr_results = {}
    for snr in [np.inf] + snr_levels:  # 包含無(wú)噪聲情況
        if snr == np.inf:
            X_input = X_test
            snr_label = "∞"
        else:
            X_input = X_test_noisy[snr]
            snr_label = f"{snr} dB"


        # 模型預(yù)測(cè)
        y_pred = model.predict(X_input)
        y_pred_cls = np.argmax(y_pred, axis=1)


        # 計(jì)算評(píng)估指標(biāo)
        acc = accuracy_score(y_test_enc, y_pred_cls)
        prec = precision_score(y_test_enc, y_pred_cls, average='macro', zero_division=0)
        rec = recall_score(y_test_enc, y_pred_cls, average='macro', zero_division=0)
        f1 = f1_score(y_test_enc, y_pred_cls, average='macro', zero_division=0)


        snr_results[snr_label] = {'acc': acc, 'prec': prec, 'rec': rec, 'f1': f1}


    # 可視化噪聲魯棒性結(jié)果
    snr_labels = list(snr_results.keys())
    acc_list = [snr_results[snr]['acc'] for snr in snr_labels]
    prec_list = [snr_results[snr]['prec'] for snr in snr_labels]
    rec_list = [snr_results[snr]['rec'] for snr in snr_labels]
    f1_list = [snr_results[snr]['f1'] for snr in snr_labels]


    plt.figure(figsize=(10, 6))
    plt.plot(snr_labels, acc_list, marker='o', label='Accuracy')
    plt.plot(snr_labels, prec_list, marker='s', label='Precision')
    plt.plot(snr_labels, rec_list, marker='^', label='Recall')
    plt.plot(snr_labels, f1_list, marker='d', label='F1-Score')
    plt.title('Model Performance under Varying SNR Levels')
    plt.xlabel('SNR (dB)')
    plt.ylabel('Score')
    plt.ylim(0.0, 1.05)
    plt.grid(True)
    plt.legend()
    plt.tight_layout()
    plt.savefig("Report/noise_robustness.pdf")
    plt.show()


    # === 信號(hào)分析 ===
    # 1. 時(shí)域分析
    def plot_time_domain(signal, title="Time-Domain Signal", sampling_rate=1000):
        time = np.linspace(0, len(signal) / sampling_rate, len(signal))
        plt.figure(figsize=(10, 3))
        plt.plot(time, signal)
        plt.title(title)
        plt.xlabel("Time (s)")
        plt.ylabel("Amplitude")
        plt.grid(True)
        plt.tight_layout()
        plt.savefig(f"Report/{title.replace(' ', '_')}.pdf")
        plt.show()


    # 2. 頻域分析
    def plot_fft(signal, sampling_rate=1000, title="Frequency Spectrum"):
        N = len(signal)
        freq = np.fft.fftfreq(N, d=1/sampling_rate)
        fft_vals = np.fft.fft(signal)
        plt.figure(figsize=(10, 3))
        plt.plot(freq[:N//2], np.abs(fft_vals)[:N//2])
        plt.title(title)
        plt.xlabel("Frequency (Hz)")
        plt.ylabel("Amplitude")
        plt.grid(True)
        plt.tight_layout()
        plt.savefig(f"Report/{title.replace(' ', '_')}.pdf")
        plt.show()


    # 應(yīng)用分析函數(shù)
    sample_signal = X_test[0].squeeze()
    plot_time_domain(sample_signal, "Normal Bearing Signal")
    plot_fft(sample_signal, "Normal Bearing Spectrum")


    # === 模型解釋性分析 ===
    # 1. 注意力權(quán)重可視化
    attention_layer = model.get_layer('time_attn1')
    attention_extractor = Model(inputs=model.input, outputs=attention_layer.output)
    attention_weights = attention_extractor.predict(X_test[:1]).squeeze()


    plt.figure(figsize=(12, 4))
    plt.plot(sample_signal, label='Input Signal')
    plt.plot(attention_weights * np.max(sample_signal), alpha=0.7, label='Attention Weights')
    plt.title('Attention Weights over Time Domain Signal')
    plt.xlabel('Time step')
    plt.legend()
    plt.savefig("Report/attention_weights.pdf")
    plt.show()


    # 2. 神經(jīng)ODE狀態(tài)演化可視化
    ode_extractor = Model(inputs=model.input, outputs=model.get_layer('time_ode').output)
    ode_outputs = ode_extractor.predict(X_test[:1]).squeeze()


    plt.figure(figsize=(12, 6))
    for i in range(5):  # 可視化5個(gè)特征
        plt.plot(ode_outputs[:, i], label=f'Feature {i+1}')
    plt.xlabel('Neural ODE Time Steps')
    plt.ylabel('Feature value')
    plt.title('Neural ODE Feature Evolution Over Time')
    plt.legend()
    plt.savefig("Report/neural_ode_evolution.pdf")
    plt.show()