我正在学习ML,MNIST集上的神经网络,我有预测概率函数的问题。我想接收我的模型预测的概率,但是当我调用函数predict_proba时,我总是收到类似于[0,0,1.,0,0,…]的数组,这意味着模型总是以100%的概率进行预测。在
你能告诉我我的模型出了什么问题,为什么会发生这种情况,以及如何解决它?在
我的模型看起来像:
# Load MNIST data set and split to train and test sets
(train_images, train_labels), (test_images, test_labels) = mnist.load_data()
# Reshaping to format which CNN expects (batch, height, width, channels)
train_images = train_images.reshape(train_images.shape[0], train_images.shape[1], train_images.shape[2], 1).astype(
"float32")
test_images = test_images.reshape(test_images.shape[0], test_images.shape[1], test_images.shape[2], 1).astype("float32")
# Normalize images from 0-255 to 0-1
train_images /= 255
test_images /= 255
# Use one hot encode to set classes
number_of_classes = 10
train_labels = keras.utils.to_categorical(train_labels, number_of_classes)
test_labels = keras.utils.to_categorical(test_labels, number_of_classes)
# Create model, add layers
model = Sequential()
model.add(Conv2D(32, (5, 5), input_shape=(train_images.shape[1], train_images.shape[2], 1), activation="relu"))
model.add(MaxPooling2D(pool_size=(2, 2)))
model.add(Conv2D(32, (3, 3), activation="relu"))
model.add(MaxPooling2D(pool_size=(2, 2)))
model.add(Dropout(0.5))
model.add(Flatten())
model.add(Dense(128, activation="relu"))
model.add(Dropout(0.5))
model.add(Dense(number_of_classes, activation="softmax"))
# Compile model
model.compile(loss="categorical_crossentropy", optimizer=Adam(), metrics=["accuracy"])
# Learn model
model.fit(train_images, train_labels, validation_data=(test_images, test_labels), epochs=7, batch_size=200)
# Test obtained model
score = model.evaluate(test_images, test_labels, verbose=0)
print("Model loss = {}".format(score[0]))
print("Model accuracy = {}".format(score[1]))
# Save model
model_filename = "cnn_model.h5"
model.save(model_filename)
print("CNN model saved in file: {}".format(model_filename))
对于加载图像,我使用PIL和NP。 我使用keras的save函数保存模型,并使用load_model from将其加载到另一个脚本中keras.型号那我就打电话来
^{pr2}$使用它看起来像:
predictor.predict_probability(predictor.load_image_for_cnn(filename))
请看代码的这一部分:
加载新图像时不执行此操作:
^{pr2}$应用与训练集相同的规范化是测试任何新图像的必要条件,如果不这样做,就会得到奇怪的结果。您只需按如下方式规范化图像像素:
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