How to fix "input shape" related errors in Keras?
Published on Aug. 22, 2023, 12:19 p.m.
I apologize, it seems like my previous response may not have been relevant to your initial question. To use pre-trained embedding vectors to initialize an embedding layer in Keras, you can follow these steps:
- Load the pre-trained embedding matrix: You can download pre-trained word embedding matrices from different sources, such as GloVe, Word2Vec, or FastText.
- Create an embedding layer with the pre-trained weights: In Keras, you can instantiate an
Embedding
layer, specify the input dimension, output dimension, and the weights matrix with pre-trained embeddings. - Use the pre-trained embedding layer in your model: You can add the pre-trained embedding layer as the first layer of your Keras model and continue to add other layers.
Here is an example of how to use pre-trained GloVe embeddings to initialize an embedding layer in Keras:
from keras.layers import Embedding
import numpy as np
# Load pre-trained GloVe embeddings
embeddings_dict = {}
with open('path_to_glove_file', 'r') as f:
for line in f:
values = line.split()
word = values[0]
vector = np.asarray(values[1:], dtype='float32')
embeddings_dict[word] = vector
# Create an embedding matrix
embedding_matrix = np.zeros((vocab_size, embedding_dim))
for word, index in word_index.items():
embedding_vector = embeddings_dict.get(word)
if embedding_vector is not None:
embedding_matrix[index] = embedding_vector
# Define the input and embedding layers
input_layer = Input(shape=(max_sequence_length,))
embedding_layer = Embedding(vocab_size, embedding_dim, weights=[embedding_matrix], input_length=max_sequence_length, trainable=False)(input_layer)
# Add additional layers to the model
# ...
# Compile and fit the model
# ...
In this example, we first load the pre-trained GloVe embeddings and create an embedding matrix that maps the word to its corresponding pre-trained embedding vector. Next, we use this matrix to initialize an embedding layer in Keras. We set the weights of the embedding layer to the pre-trained embeddings and make the layer non-trainable to keep the pre-trained weights fixed during training. Finally, we can add additional layers to the model and compile and fit the model as usual.
I hope this helps! Let me know if you have any further questions.