Run3 simpo unit test execution

Running the SimPO Unit Test

Prerequisites

• Python 3.10 environment is active
• simpo_loss function is correctly implemented in /root/SimPO/scripts/simpo_trainer.py
• All dependencies (torch, transformers, trl, accelerate, etc.) are installed

Execution Steps

# 1. Ensure correct Python
source /root/SimPO/.venv/bin/activate  # or however the venv is activated
python -VV  # Must show Python 3.10.x

# 2. Run the unit test (DO NOT modify unit_test_1.py)
cd /root/SimPO
python unit_test/unit_test_1.py

# 3. Verify output exists
python -c "import numpy as np; data = np.load('/root/loss.npz'); print('losses:', data['losses'])"

# 4. Generate the python info file
python -VV > /root/python_info.txt 2>&1
python -m pip freeze >> /root/python_info.txt

What the Unit Test Does

The unit test:

1. Creates fixed input tensors for policy_chosen_logps and policy_rejected_logps
2. Creates a SimPOTrainer (or mock) with specific beta and gamma values
3. Calls simpo_loss() with those fixed inputs
4. Saves the resulting losses to /root/loss.npz with key 'losses'

Verifying Correctness

The SimPO loss with sigmoid loss type should compute:

losses = -log(sigmoid(beta * (chosen_avg_logps - rejected_avg_logps - gamma)))

If the test provides specific beta and gamma values, you can manually verify:

import torch
import torch.nn.functional as F

# Example verification
logits = policy_chosen_logps - policy_rejected_logps - gamma
losses = -F.logsigmoid(beta * logits)

Important Notes

• Do NOT modify unit_test_1.py — it has fixed inputs for reproducibility
• The loss output must be deterministic (no randomness involved)
• Make sure self.accelerator.device is handled correctly; the unit test may mock or provide this
• If the unit test creates a minimal/mock trainer, ensure your simpo_loss method works with it