# Topic Modeling

> Extract insights from massive text datasets using cuML's GPU-accelerated BERTopic


## Table of Contents

- [Overview](#overview)
- [Instructions](#instructions)

---

## Overview

## Basic idea

Topic modeling helps you discover hidden themes in large document collections—but traditional methods crawl when datasets grow to millions of records. This playbook shows how to process **40 million Amazon product reviews in minutes** using GPU-accelerated BERTopic.

BERTopic combines transformer embeddings with clustering to extract human-readable topics from text. By swapping CPU-based UMAP and HDBSCAN with GPU-accelerated versions from **RAPIDS cuML**, you get the same results dramatically faster—no code changes required.

- **Drop-in GPU acceleration**: Load `cuml.accel` and your existing UMAP/HDBSCAN code runs on GPU automatically
- **Scale to millions**: Process datasets that would take hours on CPU in minutes on GPU
- **Interactive visualizations**: Explore topic distributions, relationships, and document clusters

## What you'll accomplish

You'll run a complete topic modeling pipeline on 40 million product reviews and generate interactive visualizations of discovered topics.

By the end, you'll be able to:
- Use cuML's drop-in accelerators for UMAP and HDBSCAN
- Generate sentence embeddings at scale with SentenceTransformers
- Create topic visualizations including heatmaps, barcharts, and document datamaps

## What to know before starting

- Experience with Python and Jupyter notebooks
- Basic understanding of machine learning concepts (embeddings, clustering)
- Familiarity with pandas DataFrames

## Prerequisites

**Hardware Requirements:**
- NVIDIA DGX Station with GB300 GPU
- Minimum 64GB GPU memory for processing 40M documents
- At least 50GB available storage for dataset and embeddings

**Software Requirements:**
- Conda (Miniconda or Anaconda): `conda --version`
- CUDA 13.0 compatible drivers: `nvidia-smi`
- Network access to download the Amazon Reviews dataset (~14GB compressed)

## Ancillary files

All required assets are in the playbook directory `nvidia/station-topic-modeling/assets` (see [Instructions](https://build.nvidia.com/station/topic-modeling/instructions), Step 7). Key file:

- `video_notebook_for_GPU_Accelerated_Machine_Learning_BERTopic_RTX6000_40M.ipynb` - Complete Jupyter notebook with GPU-accelerated topic modeling pipeline (filename reflects original demo hardware; the notebook runs on GB300 and other NVIDIA GPUs)


## Time & risk

* **Estimated time:** 45 minutes (includes environment setup, dataset download, and embedding generation)
* **Risk level:** Low
  * Large dataset download (~14GB) may take time depending on network speed
  * Embedding generation requires significant GPU memory
* **Rollback:** Delete the downloaded dataset and any generated embedding files to restore state
* **Last Updated:** 03/02/2026
  * First Publication

## Instructions

## Step 1. (DGX Station) Hugging Face cache permissions

On DGX Station, ensure the Hugging Face cache is writable so model downloads succeed:

```bash
sudo chown -R $USER:$USER $HOME/.cache/huggingface 2>/dev/null || true
sudo chmod -R u+rwX $HOME/.cache/huggingface 2>/dev/null || true
mkdir -p $HOME/.cache/huggingface
```

If you see "Permission denied" when downloading models later, run the `chown`/`chmod` lines with your username (e.g. `nvidia`).

## Step 2. Install RAPIDS cuDF and cuML

Create a new conda environment with RAPIDS libraries for GPU-accelerated data processing.

```bash
conda create -n rapids-25.10 \
  -c rapidsai -c conda-forge \
  cudf=25.10 cuml=25.10 python=3.11 'cuda-version=13.0'
```

This installs cuDF (GPU DataFrame library) and cuML (GPU machine learning library) that provide drop-in acceleration for pandas and scikit-learn operations.

## Step 3. Activate the conda environment

```bash
conda activate rapids-25.10
```

## Step 4. Install machine learning packages

Install UMAP, HDBSCAN, BERTopic, and supporting libraries for topic modeling.
Note: `datamapplot` will upgrade dask/distributed — the next step pins them back.

```bash
pip install \
  transformers datasets sentence-transformers \
  umap-learn hdbscan==0.8.40 bertopic matplotlib \
  scikit-learn==1.4.2 datamapplot
```

Pin dask/distributed back to RAPIDS-compatible versions:

```bash
pip install "dask==2025.9.1" "distributed==2025.9.1"
```

These packages provide:
- **dask**: Parallel computing library
- **distributed**: Distributed task scheduler for dask
- **sentence-transformers**: Generate text embeddings
- **umap-learn / hdbscan**: Dimensionality reduction and clustering (GPU-accelerated via cuML)
- **bertopic**: Topic modeling framework
- **datamapplot**: Document visualization

> [!NOTE]
> Pip may report dependency conflicts (e.g. dask/distributed downgraded, cuml/rapids-dask-dependency). BERTopic and the notebook can still run. If you need cuML and RAPIDS dask together, consider keeping the conda default dask versions and installing only the BERTopic stack via pip in a separate env; see **Troubleshooting**.

## Step 5. Install visualization packages

Install JupyterLab and visualization libraries for interactive topic exploration.

```bash
conda install -c conda-forge \
    notebook=7.5.0 \
    jupyterlab=4.5.0 \
    ipywidgets=8.1.8 \
    jupyterlab-widgets=3.0.16 \
    bokeh=3.8.1 \
    colorcet=3.1.0 \
    datashader=0.18.2 \
    plotly=6.5.0
```

If conda reports `PackagesNotFoundError` for `jupyterlab-widgets` (e.g. on some platforms), install it with pip:

```bash
pip install jupyterlab-widgets
```

## Step 6. Install compatible PyTorch

Install PyTorch with CUDA 13.0 support for GPU-accelerated embedding generation.

```bash
pip install torch==2.9.0 torchvision torchaudio --index-url https://download.pytorch.org/whl/cu130
```

## Step 7. Clone the repository and download the dataset

Clone the playbook repository and download the Amazon Electronics Reviews dataset.

```bash
git clone https://github.com/NVIDIA/dgx-spark-playbooks
cd dgx-spark-playbooks/nvidia/station-topic-modeling/assets
```

Download the dataset (~14GB compressed):

```bash
wget https://mcauleylab.ucsd.edu/public_datasets/data/amazon_2023/raw/review_categories/Electronics.jsonl.gz
```

## Step 8. Pull Git LFS files (notebooks)

The notebook files are stored in Git LFS — without this step, JupyterLab will throw a `NotJSONError` when trying to open them.

```bash
conda install -c conda-forge git-lfs
git lfs install
git lfs pull
```

## Step 9. Launch JupyterLab

Start JupyterLab from the assets directory:

```bash
jupyter lab
```

## Step 10. Select the rapids-25.10 kernel

In JupyterLab, open the notebook `video_notebook_for_GPU_Accelerated_Machine_Learning_BERTopic_1M.ipynb`.

Select the **rapids-25.10** kernel from the kernel selector in the top right corner of the notebook interface.

## Step 11. Execute all cells

Run all cells in the notebook sequentially. The notebook will:

1. **Load data with cuDF**: GPU-accelerated pandas via `%load_ext cudf.pandas`
2. **Preprocess text**: Clean and normalize review text
3. **Generate embeddings**: Create sentence embeddings
4. **Enable GPU acceleration**: Load cuML accelerators via `%load_ext cuml.accel`
5. **Run BERTopic**: Cluster documents into topics using GPU-accelerated UMAP and HDBSCAN
6. **Visualize results**: Generate interactive topic visualizations

## Step 12. Explore the results

After the notebook completes, you'll have:

- **Topic information table**: Discovered topics with keywords and document counts
- **Topic visualization**: Interactive 2D map of topic relationships
- **Barchart**: Top keywords for each topic
- **Heatmap**: Topic similarity matrix
- **Document datamap**: Visual clustering of documents by topic

## Step 13. Cleanup (optional)

Remove the conda environment when finished:

```bash
conda deactivate
conda env remove -n rapids-25.10
```

Remove the downloaded dataset:

```bash
rm Electronics.jsonl.gz
```

Remove generated embedding files and the cloned playbook directory if you no longer need them:

```bash
## Optional: remove Hugging Face cache (embedding cache from the notebook)
rm -rf ~/.cache/huggingface

## From the parent of dgx-spark-playbooks/, remove the cloned repo
rm -rf dgx-spark-playbooks/
```

## Next steps

Apply this workflow to your own datasets:

1. **Adjust data size**: Modify `nrows` parameter when loading data to process smaller subsets
2. **Tune clustering**: Experiment with `min_cluster_size` and `min_samples` in HDBSCAN
3. **Try different embedding models**: Swap `all-MiniLM-L6-v2` for domain-specific models
4. **Export topics**: Save the topic model using `topic_model.save()` for later analysis
5. **Monitor GPU usage**: Run `nvidia-smi -l 1` to watch GPU utilization during processing
