Deep Learning PyTorch Course, Prediction-Based Embedding

The world of deep learning is constantly evolving, and artificial neural networks are showing potential in various applications. One of them is ’embedding’. In this article, we will understand the concept of predictive-based embedding and learn how to implement it using PyTorch.

Table of Contents

1. Concept of Embedding

Embedding is the process of transforming high-dimensional data into lower dimensions. Generally, this process is used to represent the characteristics of words, sentences, images, etc., in a vector form. Deep learning models can represent input data in a more understandable form through embedding.

The purpose of embedding is to ensure that data with similar meanings are located in similar vector spaces. For example, if ‘dog’ and ‘cat’ have similar meanings, then the embedding vectors of these two words should also exist in close proximity to each other.

2. Predictive Based Embedding

Predictive based embedding is one of the existing embedding techniques that learns embedding by predicting the next word based on the given input data. Through this, relationships between words can be learned, and a meaningful vector space can be created.

A representative example of predictive-based embedding is the Skip-gram model of Word2Vec. This model operates by predicting the probability of the presence of surrounding words based on a given word.

3. PyTorch Based Implementation

In this section, we will implement predictive-based embedding using PyTorch. PyTorch is a framework that provides tensor operations and automatic differentiation functions, allowing for easy construction and training of deep learning models.

4. Preparing the Dataset

First, we need to prepare the dataset. In this example, we will use simple sentence data to learn embedding. We will define the sentence data as follows:

sentences = [
        "Deep learning is a field of machine learning.",
        "Artificial intelligence is gaining attention as a future technology.",
        "A lot of predictive models using deep learning are being developed."
    ]

Next, we will perform data preprocessing. We will separate the sentences into words and assign a unique index to each word.


from collections import Counter
from nltk.tokenize import word_tokenize

# Split sentence data into words
words = [word for sentence in sentences for word in word_tokenize(sentence)]

# Calculate word frequency
word_counts = Counter(words)

# Assign word index
word_to_idx = {word: idx for idx, (word, _) in enumerate(word_counts.items())}
idx_to_word = {idx: word for word, idx in word_to_idx.items()}

5. Model Construction

Now let’s construct the embedding model. We will use a simple neural network to convert the input words into embedding vectors and perform predictions for the given words.


import torch
import torch.nn as nn
import torch.optim as optim

class EmbedModel(nn.Module):
    def __init__(self, vocab_size, embedding_dim):
        super(EmbedModel, self).__init__()
        self.embeddings = nn.Embedding(vocab_size, embedding_dim)

    def forward(self, input):
        return self.embeddings(input)
    
# Set hyperparameters
embedding_dim = 10
vocab_size = len(word_to_idx)

# Initialize the model
model = EmbedModel(vocab_size, embedding_dim)

6. Training the Model

Now let’s train the model. We will set the loss function and use the optimizer to update the weights. We will perform the task of predicting the next word based on the given word.


# Set loss function and optimizer
loss_function = nn.CrossEntropyLoss()
optimizer = optim.SGD(model.parameters(), lr=0.01)

# Prepare training data
train_data = [(word_to_idx[words[i]], word_to_idx[words[i + 1]]) for i in range(len(words) - 1)]

# Train the model
for epoch in range(100):  # Number of epochs
    total_loss = 0
    for input_word, target_word in train_data:
        model.zero_grad()  # Reset gradients
        input_tensor = torch.tensor([input_word], dtype=torch.long)
        target_tensor = torch.tensor([target_word], dtype=torch.long)

        # Calculate model output
        output = model(input_tensor)

        # Calculate loss
        loss = loss_function(output, target_tensor)
        total_loss += loss.item()

        # Backpropagation and weight update
        loss.backward()
        optimizer.step()

    print(f"Epoch {epoch + 1}, Loss: {total_loss:.4f}")

7. Result Analysis

After training is complete, we can extract and analyze the embedding vectors for each word to visualize the relationships between words. This allows us to confirm the effectiveness of predictive-based embedding.


# Extract word embedding vectors
with torch.no_grad():
    word_embeddings = model.embeddings.weight.numpy()

# Print results
for word, idx in word_to_idx.items():
    print(f"{word}: {word_embeddings[idx]}")

8. Conclusion

In this article, we explored the concept of predictive-based embedding in deep learning and learned how to implement it using PyTorch. Embedding can be utilized in various fields, and predictive-based embedding is a useful technique for effectively expressing relationships between words. Moving forward, we hope to explore the possibilities of embedding by using more data and experimenting with various models.

I hope this article has been helpful to you. Wishing you all the best in your deep learning journey!