Keras中如何實(shí)現(xiàn)文本生成任務(wù)

小樊
82
2024-03-25 11:03:01

在Keras中實(shí)現(xiàn)文本生成任務(wù)通常使用循環(huán)神經(jīng)網(wǎng)絡(luò)(RNN)或者長(zhǎng)短時(shí)記憶網(wǎng)絡(luò)(LSTM)。以下是一個(gè)簡(jiǎn)單的例子,以生成莎士比亞風(fēng)格的文本為例:

  1. 導(dǎo)入必要的庫(kù)和模塊:
from keras.models import Sequential
from keras.layers import LSTM, Dense
  1. 準(zhǔn)備數(shù)據(jù):
text = # 輸入文本數(shù)據(jù)

maxlen = 40
step = 3
sentences = []
next_chars = []

for i in range(0, len(text) - maxlen, step):
    sentences.append(text[i: i + maxlen])
    next_chars.append(text[i + maxlen])

x = np.zeros((len(sentences), maxlen, len(chars)), dtype=np.bool)
y = np.zeros((len(sentences), len(chars)), dtype=np.bool)

for i, sentence in enumerate(sentences):
    for t, char in enumerate(sentence):
        x[i, t, char_indices[char]] = 1
    y[i, char_indices[next_chars[i]]] = 1
  1. 構(gòu)建模型:
model = Sequential()
model.add(LSTM(128, input_shape=(maxlen, len(chars)))
model.add(Dense(len(chars), activation='softmax'))

model.compile(loss='categorical_crossentropy', optimizer='rmsprop')
  1. 訓(xùn)練模型:
model.fit(x, y, batch_size=128, epochs=60)
  1. 生成文本:
def generate_text(model, start_string, length=400, temperature=0.5):
    generated = start_string
    for i in range(length):
        x_pred = np.zeros((1, maxlen, len(chars)))
        for t, char in enumerate(start_string):
            x_pred[0, t, char_indices[char]] = 1.
        
        preds = model.predict(x_pred, verbose=0)[0]
        next_index = sample(preds, temperature)
        next_char = indices_char[next_index]
        
        generated += next_char
        start_string = start_string[1:] + next_char
    return generated

以上是一個(gè)簡(jiǎn)單的文本生成任務(wù)的實(shí)現(xiàn)步驟,可以根據(jù)具體需求和數(shù)據(jù)進(jìn)行調(diào)整和優(yōu)化。

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