我们从Python开源项目中，提取了以下11个代码示例，用于说明如何使用keras.layers.TimeDistributedDense()。
def test_sequence_to_sequence(): ''' Apply a same Dense layer for each element of time dimension of the input and make predictions of the output sequence elements. This does not make use of the temporal structure of the sequence (see TimeDistributedDense for more details) ''' (X_train, y_train), (X_test, y_test) = get_test_data(nb_train=500, nb_test=200, input_shape=(3, 5), output_shape=(3, 5), classification=False) model = Sequential() model.add(TimeDistributedDense(y_train.shape[-1], input_shape=(X_train.shape[1], X_train.shape[2]))) model.compile(loss='hinge', optimizer='rmsprop') history = model.fit(X_train, y_train, nb_epoch=20, batch_size=16, validation_data=(X_test, y_test), verbose=0) assert(history.history['val_loss'][-1] < 0.8)
def build(self): dim_data = self.size_of_input_data_dim nb_time_step = self.size_of_input_timesteps financial_time_series_input = Input(shape=(nb_time_step, dim_data)) lstm_layer_1 = LSTM(output_dim=nb_hidden_units, dropout_U=dropout, dropout_W=dropout, inner_activation='sigmoid', W_regularizer=l2(l2_norm_alpha), b_regularizer=l2(l2_norm_alpha), activation='tanh', return_sequences=True) lstm_layer_2 = LSTM(output_dim=nb_hidden_units, dropout_U=dropout, dropout_W=dropout, inner_activation='sigmoid', W_regularizer=l2(l2_norm_alpha), b_regularizer=l2(l2_norm_alpha), activation='tanh', return_sequences=True) h1 = lstm_layer_1(financial_time_series_input) h2 = lstm_layer_2(h1) time_series_predictions = TimeDistributedDense(1)(h2) self.model = Model(financial_time_series_input, time_series_predictions, name="deep rnn for financial time series forecasting")
def create_temporal_sequential_model(): model = Sequential() model.add(GRU(32, input_shape=(timesteps, input_dim), return_sequences=True)) model.add(TimeDistributedDense(nb_classes)) model.add(Activation('softmax')) return model
def test_masked_temporal(): ''' Confirm that even with masking on both inputs and outputs, cross-entropies are of the expected scale. In this task, there are variable length inputs of integers from 1-9, and a random subset of unmasked outputs. Each of these outputs has a 50% probability of being the input number unchanged, and a 50% probability of being 2*input%10. The ground-truth best cross-entropy loss should, then be -log(0.5) = 0.69 ''' model = Sequential() model.add(Embedding(10, 20, mask_zero=True, input_length=20)) model.add(TimeDistributedDense(10)) model.add(Activation('softmax')) model.compile(loss='categorical_crossentropy', optimizer='adam', sample_weight_mode='temporal') X = np.random.random_integers(1, 9, (50000, 20)) for rowi in range(X.shape[0]): padding = np.random.random_integers(X.shape[1] / 2) X[rowi, :padding] = 0 # 50% of the time the correct output is the input. # The other 50% of the time it's 2 * input % 10 y = (X * np.random.random_integers(1, 2, X.shape)) % 10 Y = np.zeros((y.size, 10), dtype='int32') for i, target in enumerate(y.flat): Y[i, target] = 1 Y = Y.reshape(y.shape + (10,)) # Mask 50% of the outputs via sample weights sample_weight = np.random.random_integers(0, 1, y.shape) print('X shape:', X.shape) print('Y shape:', Y.shape) print('sample_weight shape:', Y.shape) history = model.fit(X, Y, validation_split=0.05, sample_weight=None, verbose=1, nb_epoch=2) ground_truth = -np.log(0.5) assert(np.abs(history.history['val_loss'][-1] - ground_truth) < 0.06)
def train_breaker(datafilename, sentence_num=1000, puncs=u',?.?!???', \ RNN=recurrent.GRU, HIDDEN_SIZE=128, EPOCH_SIZE=10, validate=True): wordtable = WordTable() wordtable.parse(datafilename, sentence_num) X, Y = [], [] for line in open(datafilename).readlines()[:sentence_num]: line = line.strip().decode('utf-8') line = re.sub(ur'(^[{0}]+)|([{0}]+$)'.format(puncs),'',line) words = wordtable.encode(re.sub(ur'[{0}]'.format(puncs),'',line)) breaks = re.sub(ur'0[{0}]+'.format(puncs),'1',re.sub(ur'[^{0}]'.format(puncs),'0',line)) if len(words) >= 30 and len(words) <= 50 and breaks.count('1') >= 4: x = np.zeros((len(words), wordtable.capacity), dtype=np.bool) y = np.zeros((len(breaks), 2), dtype=np.bool) for idx in xrange(len(words)): x[idx][words[idx]] = True y[idx][int(breaks[idx])] = True X.append(x) Y.append(y) print 'total sentence: ', len(X) if validate: # Set apart 10% for validation split_at = len(X) - len(X)/10 X_train, X_val = X[:split_at], X[split_at:] y_train, y_val = Y[:split_at], Y[split_at:] else: X_train, y_train = X, Y model = Graph() model.add_input(name='input', input_shape=(None, wordtable.capacity)) model.add_node(RNN(HIDDEN_SIZE, return_sequences=True), name='forward', input='input') model.add_node(TimeDistributedDense(2, activation='softmax'), name='softmax', input='forward') model.add_output(name='output', input='softmax') model.compile('adam', {'output': 'categorical_crossentropy'}) for epoch in xrange(EPOCH_SIZE): print "epoch: ", epoch for idx, (seq, label) in enumerate(zip(X_train, y_train)): loss, accuracy = model.train_on_batch({'input':np.array([seq]), 'output':np.array([label])}, accuracy=True) if idx % 20 == 0: print "\tidx={0}, loss={1}, accuracy={2}".format(idx, loss, accuracy) if validate: _Y, _P = [], [] for (seq, label) in zip(X_val, y_val): y = label.argmax(axis=-1) p = model.predict({'input':np.array([seq])})['output'][0].argmax(axis=-1) _Y.extend(list(y)) _P.extend(list(p)) _Y, _P = np.array(_Y), np.array(_P) print "should break right: ", ((_P == 1)*(_Y == 1)).sum() print "should break wrong: ", ((_P == 0)*(_Y == 1)).sum() print "should not break right: ", ((_P == 0)*(_Y == 0)).sum() print "should not break wrong: ", ((_P == 1)*(_Y == 0)).sum() with open('wordtable_json.txt','w') as wordtable_file: wordtable_file.write(wordtable.to_json()) with open('model_json.txt','w') as model_file: model_file.write(model.to_json()) model.save_weights('model_weights.h5', overwrite=True)
