Hyperparameter Tuning
Description
Hyperparameter tuning is the process of finding the best settings for a model to achieve optimal performance.
Varieties
Training a CV involves testing all possible hyperparameters in each attempt. The process consists of the following steps:
- Define the hyperparameters and their search space: Identify the hyperparameters to optimize and specify their possible value ranges.
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Choose a search strategy: Select a method to explore the hyperparameter search space, such as:
- Grid search: Systematically evaluates all possible hyperparameter combinations.
- Random search: Samples random combinations within the search space.
- Bayesian optimization: Uses a probabilistic model to guide the search, balancing exploration and exploitation.
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Perform the search: Train a model using each combination of hyperparameter values and evaluate its performance.
- Select the best hyperparameters: Choose the combination that achieves the best performance based on the evaluation metric.
Example
from sklearn.datasets import load_iris
from sklearn.linear_model import LogisticRegression
from sklearn.model_selection import GridSearchCV
X, y = load_iris(return_X_y=True)
param_grid = {"C": [0.1, 1, 10]}
clf = LogisticRegression(max_iter=200)
grid = GridSearchCV(clf, param_grid)
grid.fit(X, y)
print("Best C:", grid.best_params_["C"])