README.md

📈 PySD Streamlit App with Hugging Face Transformers

This Streamlit app allows you to:

• Upload System Dynamics models in .mdl (Vensim) or .xmile format
• Run simulations using PySD
• Visualize time series results
• Ask LLM-powered questions about your model using the Hugging Face mistralai/Mistral-7B-Instruct model

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🚀 Features

✅ Upload and simulate .mdl or .xmile models
✅ Visualize model outputs as time-series plots
✅ Ask natural language questions about model logic
✅ Integrates with Hugging Face-hosted Transformer APIs

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🧱 Installation & Usage

Step 1: Deploy as a Hugging Face Space

• Create a new Hugging Face Space and select:
  • SDK: Streamlit
  • Python version: 3.8+

Step 2: Upload Project Files

Upload the following files to the root of your Space:

• app.py
• requirements.txt
• README.md

Step 3: Set up Hugging Face Token (Optional but Recommended)

To enable transformer-powered Q&A about your model:

Option 1: Use Streamlit Secrets

1. Go to your HF Space → Settings → Secrets
2. Add the secret key:

   HF_API_TOKEN = your_hf_token_here
   

Option 2: Enter Token in App

If no token is saved in secrets, the app will prompt you to enter it interactively.

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💬 Example Questions

• “What causes the temperature to drop?”
• “Which variables form a feedback loop?”
• “Explain the relationship between stock and flow.”

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📦 Dependencies

The app uses:

• streamlit
• pysd
• matplotlib
• pandas
• requests
• lxml

All dependencies are listed in requirements.txt.

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🧠 LLM-Powered Q&A

The transformer model is queried through the Hugging Face Inference API:

• Model: mistralai/Mistral-7B-Instruct-v0.1
• Input: Parsed model component structure from PySD
• Output: Natural language explanations

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🔒 Notes

• Hugging Face Spaces have limited RAM; large models or simulations may timeout
• The .mdl model must follow Vensim conventions compatible with PySD
• Advanced CLD/SFD visualization will be added in future releases

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📞 Questions or Feedback?

Please feel free to fork or raise an issue on the repo or Hugging Face space. Contributions welcome!