wehub-resource-sync
83 lines
2.8 KiB
Markdown
83 lines
2.8 KiB
Markdown
# Evaluate a simple RAG system
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In this tutorial, we will write a simple evaluation pipeline to evaluate a RAG (Retrieval-Augmented Generation) system. At the end of this tutorial, you’ll learn how to evaluate and iterate on a RAG system using evaluation-driven development.
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```mermaid
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flowchart LR
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A["Query<br/>'What is Ragas 0.3?'"] --> B[Retrieval System]
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C[Document Corpus<br/> Ragas 0.3 Docs📄] --> B
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B --> D[LLM + Prompt]
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A --> D
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D --> E[Final Answer]
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```
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We will start by writing a simple RAG system that retrieves relevant documents from a corpus and generates an answer using an LLM.
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```bash
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python -m ragas_examples.rag_eval.rag
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```
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Next, we will write down a few sample queries and expected outputs for our RAG system. Then convert them to a CSV file.
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```python
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import pandas as pd
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samples = [
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{"query": "What is Ragas 0.3?", "grading_notes": "- Ragas 0.3 is a library for evaluating LLM applications."},
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{"query": "How to install Ragas?", "grading_notes": "- install from source - install from pip using ragas[examples]"},
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{"query": "What are the main features of Ragas?", "grading_notes": "organised around - experiments - datasets - metrics."}
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]
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pd.DataFrame(samples).to_csv("datasets/test_dataset.csv", index=False)
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```
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To evaluate the performance of our RAG system, we will define a llm based metric that compares the output of our RAG system with the grading notes and outputs pass/fail based on it.
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```python
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from ragas.metrics import DiscreteMetric
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my_metric = DiscreteMetric(
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name="correctness",
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prompt = "Check if the response contains points mentioned from the grading notes and return 'pass' or 'fail'.\nResponse: {response} Grading Notes: {grading_notes}",
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allowed_values=["pass", "fail"],
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)
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```
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Next, we will write the experiment loop that will run our RAG system on the test dataset and evaluate it using the metric, and store the results in a CSV file.
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```python
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@experiment()
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async def run_experiment(row):
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response = rag_client.query(row["query"])
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score = my_metric.score(
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llm=llm,
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response=response.get("answer", " "),
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grading_notes=row["grading_notes"]
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)
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experiment_view = {
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**row,
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"response": response.get("answer", ""),
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"score": score.value,
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"log_file": response.get("logs", " "),
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}
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return experiment_view
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```
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Now whenever you make a change to your RAG pipeline, you can run the experiment and see how it affects the performance of your RAG.
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## Running the example end to end
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1. Setup your OpenAI API key
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```bash
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export OPENAI_API_KEY="your_openai_api_key"
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```
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2. Run the evaluation
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```bash
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python -m ragas_examples.rag_eval.evals
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```
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Voila! You have successfully run your first evaluation using Ragas. You can now inspect the results by opening the `experiments/experiment_name.csv` file. |