我在尝试使用VGG16创建一个分类模型,但在项目结束时遇到了获取混淆矩阵的错误。以下是代码,
导入的包和模块如下:
import osimport kerasimport numpy as npimport tensorflow as tffrom keras.models import Modelimport matplotlib.pyplot as pltfrom keras.optimizers import Adamfrom keras.applications import MobileNetfrom sklearn.metrics import confusion_matrixfrom keras.layers.core import Dense, Activationfrom keras.metrics import categorical_crossentropyfrom sklearn.model_selection import train_test_splitfrom keras.preprocessing.image import ImageDataGeneratorfrom keras.applications.mobilenet import preprocess_inputfrom tensorflow.keras.preprocessing import image_dataset_from_directory
注意: 为了简短,我跳过了数据集的链接
下面定义VGG16:
vgg16_model = keras.applications.vgg16.VGG16()vgg16_model.summary()
现在,定义模型:
model = Sequential()for layer in vgg16_model.layers: model.add(layer)for layer in model.layers: layer.trainable = Falsemodel.add(Dense(2, activation='softmax'))
编译模型:
model.compile(Adam(lr=.0001), loss='categorical_crossentropy', metrics=['accuracy'])
训练模型:
model.fit_generator(train_batches, steps_per_epoch=4, validation_data=valid_batches, validation_steps=4, epochs=10, verbose=2)
现在获取混淆矩阵:
test_imgs, test_labels = next(test_batches)plots(test_imgs, titles=test_labels)test_labels = test_labels[:,0] predictions = model.predict_generator(test_batches, steps=1, verbose=0)cm = confusion_matrix(test_labels, np.round(predictions[:,0]))
下面我遇到了一个错误,请关注下面的代码,
cm_plot_labels = ['diseaseAffectedEggplant','freshEggplant']plot_confusion_matrix(cm, cm_plot_labels, title="Confusion Matrix") // 在这一行,我遇到了错误
错误信息如下,
---------------------------------------------------------------------------NameError Traceback (most recent call last)<ipython-input-28-43b96d543746> in <module>() 1 cm_plot_labels = ['diseaseAffectedEggplant','freshEggplant']----> 2 plot_confusion_matrix(cm, cm_plot_labels, title="Confusion Matrix")NameError: name 'plot_confusion_matrix' is not defined
回答:
您需要从sklearn.metrics
模块中导入plot_confusion_matrix
:
from sklearn.metrics import plot_confusion_matrix
请查看文档。
函数plot_confusion_matrix
在1.0版本中已被废弃,并在1.2版本中被移除。请使用类方法中的一个:ConfusionMatrixDisplay.from_predictions
或ConfusionMatrixDisplay.from_estimator
。
请查看文档