This model is a fine-tuned version of Qwen2.5-1.5B-Instruct, designed for instruction-following and structured reasoning. It is trained on an enhanced CodeAlpaca-20K dataset, incorporating Chain-of-Thought (CoT) reasoning augmented by DeepSeek AI.

Key Features

Base Model: Qwen2.5-1.5B-Instruct
Fine-Tuned On: CodeAlpaca-20K enhanced with DeepSeek-V3
Optimized for: Instruction-following, structured reasoning, and problem-solving
Fine-tuning method: LoRA (Low-Rank Adaptation)
Inference-ready: Available on Hugging Face and compatible with llama.cpp
Supports GGUF: Optimized versions for Q4_K_M, Q8_0, Q5_K_M, and FP16

Model Details

Developed by: Yiqiao Yin
Model Type: Causal Language Model (Text Generation)
Languages: English (en)
License: MIT License
Fine-tuned from: Qwen/Qwen2.5-1.5B-Instruct
Training Library: transformers + unsloth + trl
Quantization: GGUF (Q4_K_M, Q8_0, Q5_K_M, f16)

🔗 Hugging Face Repository:
👉 Fine-tuned Qwen2.5-1.5B-Instruct

How to Use the Model

Using `transformers` in Python

You may need to install bitsandbytes by using

! pip install -U bitsandbytes

Then you can use the following code to run inference.

python

from transformers import AutoModelForCausalLM, AutoTokenizer
import torch

# Load model and tokenizer
model_name = "eagle0504/qwen-2_5-1_5b-instruct-using-codealpaca-20k-enhanced-v1"
tokenizer = AutoTokenizer.from_pretrained(model_name)
model = AutoModelForCausalLM.from_pretrained(model_name)

# Move model to GPU if available
device = "cuda" if torch.cuda.is_available() else "cpu"
model.to(device)

# Example inference
question = "How do I implement a binary search algorithm in Python?"
inputs = tokenizer(question, return_tensors="pt").to(device)
output = model.generate(**inputs, max_length=200)

# Decode response
print(tokenizer.decode(output[0], skip_special_tokens=True))

Running the Model with `llama.cpp`

Step 1: Install `llama.cpp`

brew install llama.cpp

Step 2: Download the Model

mkdir -p ~/llama_models && cd ~/llama_models
wget https://huggingface.co/eagle0504/qwen-2_5-1_5b-instruct-using-codealpaca-20k-enhanced-v1/resolve/main/q8_0.gguf

Step 3: Run the Model

llama-cli -m ~/llama_models/q8_0.gguf --interactive

Or you can use the following:

llama-cli -hf eagle0504/qwen-2_5-1_5b-instruct-using-codealpaca-20k-enhanced-v1:Q8_0

Step 4: Test with a Prompt

llama-cli -m ~/llama_models/q8_0.gguf -p "Explain the differences between breadth-first search and depth-first search."

Training Details

Custom Reward

python

def count_xml(text: str) -> float:
    """
    Calculates a reward based on the occurrence of certain XML tags and subtracts penalties for content after closing tags.

    Args:
    text (str): The text string to analyze for XML tag consistency.

    Returns:
    float: Total reward score based on XML tag occurrence and penalties.
    """
    count = 0.0
    if text.count("<think>\n") == 1:
        count += 0.125
    if text.count("\n</think>\n") == 1:
        count += 0.125
    if text.count("\n<answer>\n") == 1:
        count += 0.125
        count -= len(text.split("\n</answer>\n")[-1])*0.001
    if text.count("\n</answer>") == 1:
        count += 0.125
        count -= (len(text.split("\n</answer>")[-1]) - 1)*0.001

    # Ensure `<think>` and `</think>` exist
    if "<think>" in text and "</think>" in text:
        count += 1.0  # Higher weight to ensure reasoning consistency
    else:
        count -= 1.0  # Penalize if missing

    return count

Each component contributes to the total reward if conditions are met:

Condition	Reward
`"<think>\n"` appears exactly once	+0.125
`"\n</think>\n"` appears exactly once	+0.125
`"\n<answer>\n"` appears exactly once	+0.125
`"\n</answer>"` appears exactly once	+0.125
Both `<think>` and `</think>` exist anywhere	+1.0
No extra text after `"</answer>"`	No penalty

Total possible reward before penalties: [ 0.125 + 0.125 + 0.125 + 0.125 + 1.0 = 1.5 ]

Potential Penalties The function applies penalties for extra content after "</answer>": [ -\left( \text{length of extra text} \times 0.001 \right) ] If the best case occurs (i.e., no extra content), then:

Penalty = 0
Final Reward = 1.5 (no deductions)

Best Possible Input Example This ideal input gives the highest possible reward:

xml

<think>
Valid reasoning goes here.
</think>

<answer>
Correct final answer here.
</answer>

This means we customize the reward function so that we encourage the answer to have reasoning inside. We also know mathematically what the reward should be so we can monitor it during training process.

Dataset Used

The model was fine-tuned on:
🔹 eagle0504/augmented_codealpaca-20k-using-together-ai-deepseek-v1

This dataset contains:

20K augmented training samples
Features: instruction, response, cot (Chain-of-Thought)

Training Configuration

Framework: transformers + unsloth + trl
Optimization: LoRA applied to QKV projections
Learning Rate: 1e-6
AdamW Optimizer (8-bit)
Mixed Precision (bf16 or fp16)
Batch Size: 8
Max Sequence Length: 1024

eagle0504/qwen-2_5-1_5b-instruct-using-codealpaca-20k-enhanced-v1

Qwen2.5-1.5B-Instruct Fine-Tuned on CodeAlpaca-20K with DeepSeek Augmentation

Model Overview