因此,我一直遵循Google的官方tensorflow指南,并尝试使用Keras构建一个简单的神经网络。但是,在训练模型时,它不使用整个数据集(具有60000个条目),而是仅使用1875个条目进行训练。有可能解决吗?
import tensorflow as tf from tensorflow import keras import numpy as np fashion_mnist = keras.datasets.fashion_mnist (train_images, train_labels), (test_images, test_labels) = fashion_mnist.load_data() train_images = train_images / 255.0 test_images = test_images / 255.0 class_names = ['T-shirt', 'Trouser', 'Pullover', 'Dress', 'Coat', 'Sandal', 'Shirt', 'Sneaker', 'Bag', 'Ankle Boot'] model = keras.Sequential([ keras.layers.Flatten(input_shape=(28, 28)), keras.layers.Dense(128, activation='relu'), keras.layers.Dense(10) ]) model.compile(optimizer='adam', loss= tf.keras.losses.SparseCategoricalCrossentropy(from_logits=True), metrics=['accuracy']) model.fit(train_images, train_labels, epochs=10)
输出:
Epoch 1/10 1875/1875 [==============================] - 3s 2ms/step - loss: 0.3183 - accuracy: 0.8866 Epoch 2/10 1875/1875 [==============================] - 3s 2ms/step - loss: 0.3169 - accuracy: 0.8873 Epoch 3/10 1875/1875 [==============================] - 3s 2ms/step - loss: 0.3144 - accuracy: 0.8885 Epoch 4/10 1875/1875 [==============================] - 3s 2ms/step - loss: 0.3130 - accuracy: 0.8885 Epoch 5/10 1875/1875 [==============================] - 3s 2ms/step - loss: 0.3110 - accuracy: 0.8883 Epoch 6/10 1875/1875 [==============================] - 3s 2ms/step - loss: 0.3090 - accuracy: 0.8888 Epoch 7/10 1875/1875 [==============================] - 3s 2ms/step - loss: 0.3073 - accuracy: 0.8895 Epoch 8/10 1875/1875 [==============================] - 3s 2ms/step - loss: 0.3057 - accuracy: 0.8900 Epoch 9/10 1875/1875 [==============================] - 3s 2ms/step - loss: 0.3040 - accuracy: 0.8905 Epoch 10/10 1875/1875 [==============================] - 3s 2ms/step - loss: 0.3025 - accuracy: 0.8915 <tensorflow.python.keras.callbacks.History at 0x7fbe0e5aebe0>
这是我一直在为此工作的原始Google colab笔记本:https ://colab.research.google.com/drive/1NdtzXHEpiNnelcMaJeEm6zmp34JMcN38
1875模型拟合期间显示的数字不是训练样本;它是 批 数。
1875
model.fit包括一个可选参数batch_size,根据文档所述:
model.fit
batch_size
如果未指定,batch_size则默认为32。
因此,这里发生的是-您适合默认批处理大小32(因为您没有指定其他任何东西),因此数据的批处理总数为
60000/32 = 1875