AdaBoost (Adaptive Boosting) is a binary classification ensemble learning algorithm that focuses on data points misclassified by the current ensemble.
It iteratively trains weak classifiers, assigns weights to data points, and combines them into a strong classifier. Its key steps:
- Initialization: Set equal weights for all training data points.
- Iterative Training: For each iteration, train a weak classifier, often a decision stump, on weighted data. It emphasizes misclassified data from the previous round.
- Classifier Weight Calculation: Calculate the weighted error of the weak classifier and compute its weight in the ensemble. Higher weight for better performance.
- Weight Update: Adjust data point weights based on the correctness of classification by the current weak classifier. Increase weights for misclassified points, decrease for correct ones.
- Ensemble Creation: Combine weak classifiers into an ensemble, each with its weight.
- Normalization of Weights: Ensure data point weights form a probability distribution.
- Final Classification: Compute the final prediction as the sign of the weighted sum of predictions from weak classifiers.
- Repeat Iterations: Continue iterations until a preset limit or…