pascalabcnet/InstallerSamples/MachineLearning/05_Validation/05_GridSearch_LogisticRegression.pas
Mikhalkovich Stanislav 7eaddd9a54 ML - множество примеров
ML - устранение неточностей и багов
ML - оптимизация производительности DecisionTreeRegressor.Fit, RandomForestRegressor.Fit
ML - тесты
2026-05-07 22:53:13 +03:00

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// В этом примере подбирается коэффициент регуляризации
// для LogisticRegression с помощью GridSearch.
uses MLABC;
begin
var (X, y) := Datasets.MakeClassification(
n := 400,
nFeatures := 6,
nInformative := 3,
nRedundant := 1,
noise := 0.2,
classSep := 1.0,
flipProb := 0.06,
seed := 42
);
var scaler := new StandardScaler;
scaler.Fit(X);
X := scaler.Transform(X);
var lambdaValues := [0.0, 0.01, 0.1, 0.5, 1.0, 2.0, 5.0];
Println('Подбор параметра lambda для LogisticRegression');
Println;
Println('Проверяемые значения lambda:');
foreach var lambda in lambdaValues do
begin
var score := Validation.StratifiedCrossValidate(
new LogisticRegression(lambda := lambda, learningRate := 0.05, epochs := 1000),
X, y,
5,
ClassificationMetrics.Accuracy,
seed := 42
);
Println($' lambda = {lambda,4:F2} -> средняя Accuracy = {score:F3}');
end;
Println;
var (bestLambda, bestScore, bestModel) := GridSearch.Search(
lambda -> new LogisticRegression(lambda := lambda, learningRate := 0.05, epochs := 1000),
lambdaValues,
X, y,
5,
ClassificationMetrics.Accuracy,
maximize := True,
stratified := True,
seed := 42
);
Println($'Лучшее значение lambda: {bestLambda:F2}');
Println($'Лучшая средняя Accuracy: {bestScore:F3}');
end.