LangChain / RAG / Vector DBs · レッスン

カスタム埋め込みモデルの統合

特定のドメインに最適化された表現を生成するため、カスタムまたはファインチューニング済みの埋め込みモデルを組み込む方法を学びます。

「カスタム埋め込みモデルの統合」はCoddyKit上の無料LangChain / RAG / Vector DBsレッスンです。これはレッスン2/4です。下記で完全なレッスンを無料で読むことができます。その後、ブラウザ内の組み込みコードエディタと24時間対応のAIチューターでハンズオン演習できます。これはLangChain / RAG / Vector DBs学習パスの一部であり、ウェブとCoddyKitアプリ全体で進捗が同期されます。 LangChain / RAG / Vector DBsコースには全4レッスンが含まれています。

このレッスンの一部はまだ翻訳されておらず、英語で表示されています。

Why Go Custom with Embeddings?

Standard embedding models are incredibly versatile, but sometimes your data is special. When you're dealing with very specific or niche information, generic models might not fully grasp the subtle meanings.

Custom embedding models are fine-tuned for particular domains. This means they understand your unique jargon and concepts better, leading to more accurate and relevant results.

When Custom Models Shine

Specialized embeddings are particularly useful in scenarios where precision and domain-specific understanding are critical:

Medical Research: Understanding complex biological terms or patient records.
Legal Documents: Distinguishing subtle legal nuances and case precedents.
Proprietary Data: When sensitive information cannot leave your local environment or specific cloud instance.

They lead to significantly more relevant retrieval in RAG systems.

LangChain & Hugging Face Models

LangChain makes it straightforward to integrate custom or open-source embedding models, especially those available on Hugging Face. The HuggingFaceEmbeddings class is your primary tool for this.

You simply specify the model name (e.g., a sentence-transformers model), and LangChain handles loading it, often downloading it to your local machine for offline use.

Setting Up Your Environment

Before you can use Hugging Face models within LangChain, you'll need to install a few essential Python libraries:

langchain-community: Provides the HuggingFaceEmbeddings class.
sentence-transformers: The core library for running these models.
torch or tensorflow: A deep learning framework that the models depend on.

You can install them using pip:
pip install langchain-community sentence-transformers torch

Generating Embeddings with a Local Model

Let's generate an embedding for a simple sentence using a popular, small sentence-transformer model. This demonstrates how to initialize and use a custom model.

from langchain_community.embeddings import HuggingFaceEmbeddings

def main():
    # Load a local sentence-transformer model.
    # This model will be downloaded to your machine if not present.
    model_name = "all-MiniLM-L6-v2"
    embeddings = HuggingFaceEmbeddings(model_name=model_name)

    text = "This is a custom embedding example using a local model."
    query_result = embeddings.embed_query(text)

    print(f"Embedding dimensions: {len(query_result)}")
    print(f"First 5 dimensions: {query_result[:5]}")

if __name__ == "__main__":
    main()

Decoding the Embedding Code

In the previous example, we performed these key steps:

We imported HuggingFaceEmbeddings from langchain_community.
We initialized it with "all-MiniLM-L6-v2", a popular, efficient model.
The embed_query() method took our text and converted it into a numerical vector (the embedding), which captures its semantic meaning.

The model itself is downloaded and run locally, offering privacy and potentially faster inference.

Custom Embeddings in RAG

Custom embeddings are most effective when integrated into your RAG pipeline. They replace generic embeddings at the point where you build your vector store.

When you load documents, split them into chunks, and then generate embeddings for storage, you'll use your custom model. This ensures that the retrieval process is highly relevant to your specific domain or dataset.

Vector Store Integration Example

Here's how to use your HuggingFaceEmbeddings instance when creating and interacting with a vector database like Chroma DB. This ensures all stored and queried documents use your specialized model.

from langchain_community.embeddings import HuggingFaceEmbeddings
from langchain_community.vectorstores import Chroma
from langchain.docstore.document import Document
import os
import shutil

def main():
    # Define a temporary directory for Chroma DB
    persist_directory = "./chroma_db_custom_embed"
    if os.path.exists(persist_directory):
        shutil.rmtree(persist_directory)
    os.makedirs(persist_directory)

    # Load custom embedding model
    model_name = "all-MiniLM-L6-v2"
    embeddings = HuggingFaceEmbeddings(model_name=model_name)

    # Create some sample documents
    documents = [
        Document(page_content="The patient exhibited symptoms of acute respiratory distress."),
        Document(page_content="Legal precedents often guide future court decisions."),
        Document(page_content="This is a general statement about technology."),
    ]

    # Create a Chroma vector store with custom embeddings
    vectordb = Chroma.from_documents(
        documents=documents,
        embedding=embeddings,
        persist_directory=persist_directory
    )
    vectordb.persist() # Save the database to disk

    # Perform a similarity search using the same custom embeddings
    query = "What medical conditions were observed?"
    docs = vectordb.similarity_search(query)

    print(f"Query: '{query}'")
    print("\nRetrieved documents:")
    for i, doc in enumerate(docs):
        print(f"{i+1}. {doc.page_content}")

    # Clean up the temporary directory
    shutil.rmtree(persist_directory)

if __name__ == "__main__":
    main()

Why Choose Custom Embeddings?

Recap the compelling reasons to opt for custom or fine-tuned embedding models:

Domain Relevance: Achieve a deeper, more accurate understanding of specialized language and concepts.
Improved Accuracy: Leads to more precise document retrieval, enhancing the quality of RAG outputs.
Cost Efficiency: May be more economical than continuously calling API-based commercial models for high-volume use.
Data Privacy: Process embeddings locally, keeping sensitive data within your control.
Flexibility: Leverage open-source models or fine-tune your own for ultimate customization.

Test Your Knowledge

Custom embedding models offer several advantages, especially for specific use cases in a RAG system.

Custom Embeddings: The Takeaway

You've learned how custom embedding models provide a powerful way to tailor your RAG system's understanding to specific domains.

By leveraging tools like LangChain's HuggingFaceEmbeddings, you can integrate specialized models for improved accuracy, privacy, and cost efficiency in your applications.

Next, we'll explore extending retrieval chains with custom logic to further refine your RAG applications' behavior.

よくある質問

「カスタム埋め込みモデルの統合」レッスンは無料ですか？

はい。「カスタム埋め込みモデルの統合」の完全なテキストはこのウェブで無料で読めます。インタラクティブに演習し（組み込みコードエディタと24時間対応のAIチューター）、LangChain / RAG / Vector DBsコースの残りをアンロックするには、CoddyKit PROにアップグレードしてください。 LangChain / RAG / Vector DBsコースには全4レッスンが含まれています。

「カスタム埋め込みモデルの統合」で何を学びますか？

特定のドメインに最適化された表現を生成するため、カスタムまたはファインチューニング済みの埋め込みモデルを組み込む方法を学びます。ブラウザで直接実行するハンズオンコードでLangChain / RAG / Vector DBsを演習し、24時間対応のAIチューターがレッスンを進める中での質問に答えます。

LangChain / RAG / Vector DBsを始めるのに経験は必要ですか？

事前経験は必要ありません。CoddyKitのLangChain / RAG / Vector DBsは初級者から上級者向けに構成されているため、ここから始めるか最初から始めて、自分のペースで進むことができます。これはレッスン2/4です。

「カスタム埋め込みモデルの統合」レッスンにはどのくらい時間がかかりますか？

ほとんどのCoddyKitレッスンは約5～10分かかります。各レッスンはコンパクトでインタラクティブなので、着実に進歩し、ウェブとアプリ全体で正確に前回の場所から再開できます。

このLangChain / RAG / Vector DBsレッスンでコードを書いて実行できますか？

はい。すべてのLangChain / RAG / Vector DBsレッスンに組み込みコードエディタが含まれているため、ブラウザでリアルコードを書いて実行し、即座のAIフィードバックを取得できます。ローカル設定は不要です。

このコースのすべてのレッスン

← LangChain / RAG / Vector DBsに戻る