- Simple Linear Regression => Notebook | Notes
- Multiple Linear Regression => Notebook | Notes
- Lasso Regression => Notebook | Notes
- Ridge Regression => Notebook | Notes
- Support Vector Regression (SVR)
- Decision Trees Regression
- Random Forest Regression
- Gradient Boosting Regression
- Neural Networks Regression
Before selecting an algorithm, thoroughly analyze your dataset.
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Explore Data Characteristics:
- Distribution of the target variable (e.g., normal, skewed, multimodal).
- Relationship between features and target (linear vs. non-linear).
- Presence of categorical or numerical features.
- Dimensionality of the data (number of features vs. number of samples).
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Check Data Quality:
- Missing values.
- Outliers.
- Imbalanced data (if the regression has grouped outputs).
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Identify Feature Interactions:
- Correlations or multicollinearity.
- Non-linear relationships.
Establish how model performance will be evaluated. Common metrics include:
- Mean Squared Error (MSE): Sensitive to large errors.
- Mean Absolute Error (MAE): Less sensitive to outliers.
- R-squared (R²): Measures explained variance.
- Root Mean Squared Error (RMSE): Square-root of MSE for interpretability.
Understand the strengths and weaknesses of different regression algorithms.
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Linear vs. Non-linear Relationships:
- Linear Regression: Best for linear relationships.
- Polynomial Regression: Captures non-linear relationships but may overfit with high degrees.
- Tree-based Methods (e.g., Decision Trees, Random Forest, Gradient Boosting): Handle non-linear relationships effectively.
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Interpretability:
- Linear Regression, Lasso, Ridge: Coefficients directly show feature importance.
- Ensemble Methods: Less interpretable but powerful.
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Handling Outliers:
- Robust Regression: Explicitly handles outliers.
- Tree-based Methods: Less sensitive to outliers.
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Handling High Dimensionality:
- Lasso Regression: Performs feature selection by penalizing irrelevant features.
- Ridge Regression: Handles multicollinearity without feature elimination.
- Principal Component Regression (PCR): Reduces dimensionality before regression.
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Scalability:
- Linear Models (e.g., OLS): Efficient for large datasets.
- Gradient Boosting (e.g., XGBoost, LightGBM): Scales well but can be computationally intensive.
- Neural Networks: Require large data to avoid overfitting.
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Data Size and Complexity:
- Small Dataset: Prefer simpler models (Linear Regression, Ridge, Lasso).
- Large, Complex Dataset: Consider Gradient Boosting, Random Forest, or Neural Networks.
Experiment with different models to identify the most suitable one.
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Baseline Model:
- Start with a simple model like Linear Regression for benchmarking.
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Train and Test Multiple Models:
- Use train-test split or cross-validation to evaluate.
- Compare algorithms like:
- Linear Regression
- Ridge and Lasso
- Decision Trees
- Random Forest
- Gradient Boosting (XGBoost, LightGBM)
- Support Vector Machines (with RBF kernel for non-linear relationships)
- Neural Networks (if data size is sufficient)
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Hyperparameter Tuning:
- Use Grid Search or Random Search to optimize model parameters.
Take into account practical considerations:
- Explainability: Is model interpretability critical for stakeholders? (e.g., healthcare or finance).
- Computational Resources: Are there limitations on training time or memory?
- Deployment: Will the model be deployed in a low-latency environment?
Follow these steps iteratively:
- Explore the data.
- Understand the problem requirements and constraints.
- Compare model performance using metrics.
- Tune the best-performing models.
- Select the most appropriate algorithm based on performance, explainability, and deployment considerations.