RNN-class
""" To know more or get code samples, please visit my website: https://morvanzhou.github.io/tutorials/ Or search: 莫烦Python Thank you for supporting! """ # please note, all tutorial code are running under python3.5. # If you use the version like python2.7, please modify the code accordingly # 8 - RNN Classifier example # to try tensorflow, un-comment following two lines # import os # os.environ['KERAS_BACKEND']='tensorflow' import numpy as np np.random.seed(1337) # for reproducibility from keras.datasets import mnist from keras.utils import np_utils from keras.models import Sequential from keras.layers import SimpleRNN, Activation, Dense from keras.optimizers import Adam TIME_STEPS = 28 # same as the height of the image INPUT_SIZE = 28 # same as the width of the image BATCH_SIZE = 50 BATCH_INDEX = 0 OUTPUT_SIZE = 10 CELL_SIZE = 50 LR = 0.001 # download the mnist to the path '~/.keras/datasets/' if it is the first time to be called # X shape (60,000 28x28), y shape (10,000, ) (X_train, y_train), (X_test, y_test) = mnist.load_data() # data pre-processing X_train = X_train.reshape(-1, 28, 28) / 255. # normalize X_test = X_test.reshape(-1, 28, 28) / 255. # normalize y_train = np_utils.to_categorical(y_train, num_classes=10) y_test = np_utils.to_categorical(y_test, num_classes=10) # build RNN model model = Sequential() # RNN cell model.add(SimpleRNN( # for batch_input_shape, if using tensorflow as the backend, we have to put None for the batch_size. # Otherwise, model.evaluate() will get error. batch_input_shape=(None, TIME_STEPS, INPUT_SIZE), # Or: input_dim=INPUT_SIZE, input_length=TIME_STEPS, output_dim=CELL_SIZE, unroll=True, )) # output layer model.add(Dense(OUTPUT_SIZE)) model.add(Activation('softmax')) # optimizer adam = Adam(LR) model.compile(optimizer=adam, loss='categorical_crossentropy', metrics=['accuracy']) # training for step in range(4001): # data shape = (batch_num, steps, inputs/outputs) X_batch = X_train[BATCH_INDEX: BATCH_INDEX+BATCH_SIZE, :, :] Y_batch = y_train[BATCH_INDEX: BATCH_INDEX+BATCH_SIZE, :] cost = model.train_on_batch(X_batch, Y_batch) BATCH_INDEX += BATCH_SIZE BATCH_INDEX = 0 if BATCH_INDEX >= X_train.shape[0] else BATCH_INDEX if step % 500 == 0: cost, accuracy = model.evaluate(X_test, y_test, batch_size=y_test.shape[0], verbose=False) print('test cost: ', cost, 'test accuracy: ', accuracy)