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Example Script: example_lasso_regress.py

This script demonstrates how to use the LassoRegressionModel class from the SciREX library to perform regression on synthetic data.

The example includes
  • Generating synthetic regression data using sklearn
  • Fitting the Lasso Regression model
  • Evaluating the model's performance using regression metrics
  • Visualizing the results
Dependencies
  • numpy
  • scikit-learn
  • matplotlib
  • scirex.core.ml.supervised.regression.lasso_regression
Authors
  • Paranidharan (paranidharan@iisc.ac.in)
Version Info
  • 16/Jan/2025: Initial version

Lasso Regression Example Documentation

Introduction

This example demonstrates the usage of the LassoRegressionModel class from the SciREX library to perform regression on synthetic data. Lasso Regression is a regularization technique that helps mitigate overfitting by adding a penalty proportional to the absolute value of the coefficients, leading to sparse models.

Workflow Overview

The example covers the following steps:

  1. Generating synthetic regression data using sklearn.
  2. Fitting the Lasso Regression model.
  3. Evaluating the model's performance using regression metrics.
  4. Visualizing the results.

Requirements

Ensure the following dependencies are installed before running the script:

  • numpy
  • scikit-learn
  • matplotlib
  • SciREX library

Install missing dependencies using pip: 

pip install numpy scikit-learn matplotlib

Example Script

Here is the complete example script:

import numpy as np
from sklearn.datasets import make_regression
from scirex.core.ml.supervised.regression.lasso_regression import LassoRegressionModel

# Generate synthetic regression data
X, y = make_regression(
    n_samples=100,
    n_features=1,
    noise=10,
    random_state=42
)

# Initialize the Lasso Regression model
lasso_model = LassoRegressionModel(alpha=1.0, random_state=42)

# Fit the model
lasso_model.fit(X, y)

# Make predictions
y_pred_lasso = lasso_model.predict(X)

# Get the model parameters
params_lasso = lasso_model.get_model_params()

# Print model parameters
print("Lasso Regression Model Parameters:")
print(f"Coefficients: {params_lasso['coefficients']}")
print(f"Intercept: {params_lasso['intercept']}")

# Evaluate the model's performance
metrics_lasso = lasso_model.evaluation_metrics(y, y_pred_lasso)
print("\nLasso Regression Evaluation Metrics:")
print(f"MSE: {metrics_lasso['mse']:.2f}")
print(f"MAE: {metrics_lasso['mae']:.2f}")
print(f"R2 Score: {metrics_lasso['r2']:.2f}")

# Visualize the regression results
lasso_model.plot_regression_results(y, y_pred_lasso)

Key Steps Explained

1. Generating Synthetic Data

We use sklearn.datasets.make_regression to create a synthetic dataset with one feature and added noise for demonstration purposes:

X, y = make_regression(
    n_samples=100,
    n_features=1,
    noise=10,
    random_state=42
)

2. Initializing the Model

We initialize the LassoRegressionModel with an alpha value for regularization and a fixed random state for reproducibility:

lasso_model = LassoRegressionModel(alpha=1.0, random_state=42)

3. Fitting the Model

Train the model using the fit method:

lasso_model.fit(X, y)

4. Predictions

Make predictions using the trained model:

y_pred_lasso = lasso_model.predict(X)

5. Retrieving Model Parameters

Retrieve the coefficients and intercept:

params_lasso = lasso_model.get_model_params()

6. Evaluating Performance

Evaluate the model using common regression metrics such as MSE, MAE, and R2 Score:

metrics_lasso = lasso_model.evaluation_metrics(y, y_pred_lasso)

7. Visualization

Visualize the regression results using the built-in plotting function:

lasso_model.plot_regression_results(y, y_pred_lasso)

Sample Output

Here’s an example of the output you can expect:

Lasso Regression Model Parameters:
Coefficients: 
Intercept: 

Lasso Regression Evaluation Metrics:
MSE: 
MAE:
R2 Score:

The visualization will show the actual vs. predicted values on a scatter plot with the regression line.

Conclusion

This example showcases how to use the LassoRegressionModel class from SciREX for regression tasks. Lasso Regression is particularly useful when feature selection and sparsity are important in models.

For more advanced use cases and detailed documentation, visit the SciREX Documentation.

Author

This example was authored by Paranidharan (paranidharan@iisc.ac.in).

License

This script is part of the SciREX library and is licensed under the Apache License 2.0. For more information, visit Apache License 2.0.