> ## Documentation Index
> Fetch the complete documentation index at: https://sourcetable.com/docs/llms.txt
> Use this file to discover all available pages before exploring further.

# Machine learning

> Build classification, regression, and clustering models with TabPFN and scikit-learn.

Sourcetable supports two ML approaches: **TabPFN** for instant zero-shot predictions, and **scikit-learn** for full model training pipelines.

## TabPFN — zero-shot predictions

TabPFN is a pre-trained neural network that makes predictions on tabular data without any training step. It works immediately on your data.

```
"Predict which customers will churn based on their usage data using TabPFN"
```

### When to use TabPFN

* Small to medium datasets (under 10,000 rows works best)
* Quick prototyping — get results in seconds
* No hyperparameter tuning needed
* Classification and regression tasks

### Available modes

| Mode           | Chat mode    | Description                                                     |
| -------------- | ------------ | --------------------------------------------------------------- |
| Classification | **Classify** | Predict categorical outcomes (churn/no churn, fraud/legitimate) |
| Regression     | **Predict**  | Predict continuous values (price, score, duration)              |

## scikit-learn — full ML pipeline

For larger datasets or when you need more control, Sourcetable uses scikit-learn under the hood.

### Classification

```
"Build a random forest classifier to predict loan default from the applicant data"
```

Available algorithms:

| Algorithm           | Best for                                          |
| ------------------- | ------------------------------------------------- |
| Random Forest       | General purpose, handles mixed features well      |
| Gradient Boosting   | High accuracy, handles non-linear relationships   |
| Logistic Regression | Interpretable, good baseline                      |
| SVM                 | High-dimensional data, clear margin of separation |
| k-Nearest Neighbors | Simple, non-parametric                            |
| Decision Tree       | Interpretable, visual output                      |
| Naive Bayes         | Text classification, very fast                    |

### Regression

```
"Train a gradient boosting model to predict house prices"
```

Available algorithms: Linear Regression, Ridge, Lasso, ElasticNet, Random Forest Regressor, Gradient Boosting Regressor, SVR, Decision Tree Regressor.

### Clustering

```
"Cluster customers into segments based on purchase behavior"
```

| Algorithm        | Best for                                   |
| ---------------- | ------------------------------------------ |
| K-Means          | Spherical clusters, known number of groups |
| DBSCAN           | Arbitrary shapes, automatic cluster count  |
| Hierarchical     | Dendrogram visualization, nested groups    |
| Gaussian Mixture | Overlapping clusters, soft assignments     |

### Dimensionality reduction

```
"Reduce the dataset to 2 dimensions with PCA and plot the clusters"
```

Available methods: PCA, t-SNE, UMAP, LDA.

## End-to-end ML pipeline

When you ask the AI to build a model, it automatically handles:

1. **Data splitting** — train/test split (default 80/20)
2. **Feature preprocessing** — encoding categoricals, scaling numerics, handling missing values
3. **Model training** — fits the chosen algorithm
4. **Evaluation** — generates metrics and visualizations
5. **Results** — writes predictions back to your spreadsheet

## Model evaluation

The AI reports relevant metrics based on the task:

**Classification metrics:**

* Accuracy, Precision, Recall, F1 Score
* ROC curve and AUC
* Confusion matrix
* Classification report by class

**Regression metrics:**

* R-squared and Adjusted R-squared
* MAE (Mean Absolute Error)
* RMSE (Root Mean Squared Error)
* Residual plots

**Clustering metrics:**

* Silhouette score
* Calinski-Harabasz index
* Inertia (for K-Means)

## Hyperparameter tuning

```
"Tune the random forest hyperparameters using cross-validation"
```

The AI performs grid search or randomized search with cross-validation to find optimal parameters.