正确预处理1D CNN的csv数据



我在准备数据集以提供1D CNN时遇到问题。

我的CSV有3025个列,表示单个字节+最后一个列作为字符串标签。

也许这不是预处理的问题,而是我的网络模型的问题。

这是我的型号:

def cnn_1d(num_classes):
model = models.Sequential()
model.add(Conv1D(16, kernel_size=3, strides=1, activation="relu", input_shape=(3025, 1)))
model.add(Conv1D(16, kernel_size=3, strides=1, activation="relu"))
model.add(MaxPooling1D(pool_size=2))
model.add(Dropout(0.2))
model.add(Conv1D(32, kernel_size=3, strides=1, activation="relu"))
model.add(Conv1D(32, kernel_size=3, strides=1, activation="relu"))
model.add(MaxPooling1D(pool_size=2))
model.add(Dropout(0.2))
model.add(Dense(500, activation="relu"))
model.add(Dense(300, activation="relu"))
model.add(Dense(num_classes, activation="softmax"))
model.compile(
optimizer=keras.optimizers.Adam(1e-3),
loss="categorical_crossentropy",
metrics=["accuracy"],
)
model.summary()
return model

这就是我试图预处理数据的方法:

num_classes = 4
df = pd.read_csv("test.csv", header=0)
df["label"] = pd.Categorical(df["label"])
df["label"] = df.label.cat.codes
Y = df.pop("label")
X = df.copy()
x_train, x_test, y_train, y_test = train_test_split(np.asarray(X), np.asarray(Y), test_size=0.33, shuffle=True)
x_train = np.reshape(x_train, (x_train.shape[0], x_train.shape[1], 1))
x_test = np.reshape(x_test, (x_test.shape[0], x_test.shape[1], 1))
model = cnn_1d(num_classes)
model.fit(x_train, y_train, epochs=100, batch_size=64, validation_data=(x_test, y_test))

我想我在最后一个密集层上得到了一个错误,因为标签预处理不正确。这个i

ValueError: Shapes (None, 1) and (None, 753, 4) are incompatible

我缺少什么?我所知道的是,最后一个密集层应该有num个类作为单位计数(在我的例子中是4(。

这是您上面展示的代码的模型摘要:

Model: "sequential_1"
_________________________________________________________________
Layer (type)                 Output Shape              Param #   
=================================================================
conv1d (Conv1D)              (None, 3023, 16)          64        
_________________________________________________________________
conv1d_1 (Conv1D)            (None, 3021, 16)          784       
_________________________________________________________________
max_pooling1d (MaxPooling1D) (None, 1510, 16)          0         
_________________________________________________________________
dropout (Dropout)            (None, 1510, 16)          0         
_________________________________________________________________
conv1d_2 (Conv1D)            (None, 1508, 32)          1568      
_________________________________________________________________
conv1d_3 (Conv1D)            (None, 1506, 32)          3104      
_________________________________________________________________
max_pooling1d_1 (MaxPooling1 (None, 753, 32)           0         
_________________________________________________________________
dropout_1 (Dropout)          (None, 753, 32)           0         
_________________________________________________________________
dense (Dense)                (None, 753, 500)          16500     
_________________________________________________________________
dense_1 (Dense)              (None, 753, 300)          150300    
_________________________________________________________________
dense_2 (Dense)              (None, 753, 4)            1204      
=================================================================
Total params: 173,524
Trainable params: 173,524
Non-trainable params: 0

输出层的维度为(批、序列长度、4个类(。您可能是想在第二个最大冷却层之后使矩阵变平。

如果我这样做,我会得到一个参数较少的模型,它将输出4个类中的一个。。。

def cnn_1d(num_classes):
model = models.Sequential()
model.add(Conv1D(16, kernel_size=3, strides=1, activation="relu", input_shape=(3025, 1)))
model.add(Conv1D(16, kernel_size=3, strides=1, activation="relu"))
model.add(MaxPooling1D(pool_size=2))
model.add(Dropout(0.2))
model.add(Conv1D(32, kernel_size=3, strides=1, activation="relu"))
model.add(Conv1D(32, kernel_size=3, strides=1, activation="relu"))
model.add(MaxPooling1D(pool_size=2))
model.add(Flatten())
model.add(Dropout(0.2))
model.add(Dense(500, activation="relu"))
model.add(Dense(300, activation="relu"))
model.add(Dense(num_classes, activation="softmax"))
model.compile(
optimizer=keras.optimizers.Adam(1e-3),
loss="categorical_crossentropy",
metrics=["accuracy"],
)
model.summary()
return model

cnn_1d(4)
Model: "sequential_2"
_________________________________________________________________
Layer (type)                 Output Shape              Param #   
=================================================================
conv1d_4 (Conv1D)            (None, 3023, 16)          64        
_________________________________________________________________
conv1d_5 (Conv1D)            (None, 3021, 16)          784       
_________________________________________________________________
max_pooling1d_2 (MaxPooling1 (None, 1510, 16)          0         
_________________________________________________________________
dropout_2 (Dropout)          (None, 1510, 16)          0         
_________________________________________________________________
conv1d_6 (Conv1D)            (None, 1508, 32)          1568      
_________________________________________________________________
conv1d_7 (Conv1D)            (None, 1506, 32)          3104      
_________________________________________________________________
max_pooling1d_3 (MaxPooling1 (None, 753, 32)           0         
_________________________________________________________________
flatten (Flatten)            (None, 24096)             0         
_________________________________________________________________
dropout_3 (Dropout)          (None, 24096)             0         
_________________________________________________________________
dense_3 (Dense)              (None, 500)               12048500  
_________________________________________________________________
dense_4 (Dense)              (None, 300)               150300    
_________________________________________________________________
dense_5 (Dense)              (None, 4)                 1204      
=================================================================
Total params: 12,205,524
Trainable params: 12,205,524
Non-trainable params: 0

此外,该模型的可训练参数明显较少。

我发现了我缺少的东西:

  1. 我错过了在y_*变量上使用to_categorical。我认为它已经和df["label"] = pd.Categorical(df["label"])分类了。所以在模型之前,我添加了:
    y_train = to_categorical(y_train, 4)
    y_test = to_categorical(y_test, 4)
    
  2. 我忘记了在最后一个MaxPool1D层之后压平输出

现在它可以正常工作了。

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