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StandardTrainersCatalog.LbfgsMaximumEntropy Méthode

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Définition

Espace de noms:
Microsoft.ML
Assembly:
Microsoft.ML.StandardTrainers.dll
Paquet:
Microsoft.ML v3.0.1
Paquet:
Microsoft.ML v1.0.0
Paquet:
Microsoft.ML v1.1.0
Paquet:
Microsoft.ML v1.2.0
Paquet:
Microsoft.ML v1.3.1
Paquet:
Microsoft.ML v1.4.0
Paquet:
Microsoft.ML v1.5.5
Paquet:
Microsoft.ML v1.6.0
Paquet:
Microsoft.ML v1.7.0
Paquet:
Microsoft.ML v2.0.0

Surcharges

LbfgsMaximumEntropy(MulticlassClassificationCatalog+MulticlassClassificationTrainers, LbfgsMaximumEntropyMulticlassTrainer+Options)

Créez LbfgsMaximumEntropyMulticlassTrainer avec des options avancées, ce qui prédit une cible à l’aide d’un modèle de classification d’entropie maximale entraîné avec la méthode L-BFGS.
LbfgsMaximumEntropy(MulticlassClassificationCatalog+MulticlassClassificationTrainers, String, String, String, Single, Single, Single, Int32, Boolean)

Créez LbfgsMaximumEntropyMulticlassTrainer, qui prédit une cible à l’aide d’un modèle de classification d’entropie maximal entraîné avec la méthode L-BFGS.

LbfgsMaximumEntropy(MulticlassClassificationCatalog+MulticlassClassificationTrainers, LbfgsMaximumEntropyMulticlassTrainer+Options)

Créez LbfgsMaximumEntropyMulticlassTrainer avec des options avancées, ce qui prédit une cible à l’aide d’un modèle de classification d’entropie maximale entraîné avec la méthode L-BFGS.

public static Microsoft.ML.Trainers.LbfgsMaximumEntropyMulticlassTrainer LbfgsMaximumEntropy (this Microsoft.ML.MulticlassClassificationCatalog.MulticlassClassificationTrainers catalog, Microsoft.ML.Trainers.LbfgsMaximumEntropyMulticlassTrainer.Options options);
static member LbfgsMaximumEntropy : Microsoft.ML.MulticlassClassificationCatalog.MulticlassClassificationTrainers * Microsoft.ML.Trainers.LbfgsMaximumEntropyMulticlassTrainer.Options -> Microsoft.ML.Trainers.LbfgsMaximumEntropyMulticlassTrainer
<Extension()>
Public Function LbfgsMaximumEntropy (catalog As MulticlassClassificationCatalog.MulticlassClassificationTrainers, options As LbfgsMaximumEntropyMulticlassTrainer.Options) As LbfgsMaximumEntropyMulticlassTrainer

Paramètres

catalog
MulticlassClassificationCatalog.MulticlassClassificationTrainers

Le MulticlassClassificationCatalog.MulticlassClassificationTrainers.

options
LbfgsMaximumEntropyMulticlassTrainer.Options

Arguments avancés de l’algorithme.

Retours

LbfgsMaximumEntropyMulticlassTrainer

Exemples

using System;
using System.Collections.Generic;
using System.Linq;
using Microsoft.ML;
using Microsoft.ML.Data;
using Microsoft.ML.Trainers;

namespace Samples.Dynamic.Trainers.MulticlassClassification
{
    public static class LbfgsMaximumEntropyWithOptions
    {
        public static void Example()
        {
            // Create a new context for ML.NET operations. It can be used for
            // exception tracking and logging, as a catalog of available operations
            // and as the source of randomness. Setting the seed to a fixed number
            // in this example to make outputs deterministic.
            var mlContext = new MLContext(seed: 0);

            // Create a list of training data points.
            var dataPoints = GenerateRandomDataPoints(1000);

            // Convert the list of data points to an IDataView object, which is
            // consumable by ML.NET API.
            var trainingData = mlContext.Data.LoadFromEnumerable(dataPoints);

            // Define trainer options.
            var options = new LbfgsMaximumEntropyMulticlassTrainer.Options
            {
                HistorySize = 50,
                L1Regularization = 0.1f,
                NumberOfThreads = 1
            };

            // Define the trainer.
            var pipeline =
                // Convert the string labels into key types.
                mlContext.Transforms.Conversion.MapValueToKey("Label")
                // Apply LbfgsMaximumEntropy multiclass trainer.
                .Append(mlContext.MulticlassClassification.Trainers
                .LbfgsMaximumEntropy(options));

            // Train the model.
            var model = pipeline.Fit(trainingData);

            // Create testing data. Use different random seed to make it different
            // from training data.
            var testData = mlContext.Data
                .LoadFromEnumerable(GenerateRandomDataPoints(500, seed: 123));

            // Run the model on test data set.
            var transformedTestData = model.Transform(testData);

            // Convert IDataView object to a list.
            var predictions = mlContext.Data
                .CreateEnumerable<Prediction>(transformedTestData,
                reuseRowObject: false).ToList();

            // Look at 5 predictions
            foreach (var p in predictions.Take(5))
                Console.WriteLine($"Label: {p.Label}, " +
                    $"Prediction: {p.PredictedLabel}");

            // Expected output:
            //   Label: 1, Prediction: 1
            //   Label: 2, Prediction: 2
            //   Label: 3, Prediction: 2
            //   Label: 2, Prediction: 2
            //   Label: 3, Prediction: 3

            // Evaluate the overall metrics
            var metrics = mlContext.MulticlassClassification
                .Evaluate(transformedTestData);

            PrintMetrics(metrics);

            // Expected output:
            //   Micro Accuracy: 0.91
            //   Macro Accuracy: 0.91
            //   Log Loss: 0.22
            //   Log Loss Reduction: 0.80

            //   Confusion table
            //             ||========================
            //   PREDICTED ||     0 |     1 |     2 | Recall
            //   TRUTH     ||========================
            //           0 ||   147 |     0 |    13 | 0.9188
            //           1 ||     0 |   165 |    12 | 0.9322
            //           2 ||    11 |     7 |   145 | 0.8896
            //             ||========================
            //   Precision ||0.9304 |0.9593 |0.8529 |
        }

        // Generates random uniform doubles in [-0.5, 0.5)
        // range with labels 1, 2 or 3.
        private static IEnumerable<DataPoint> GenerateRandomDataPoints(int count,
            int seed = 0)

        {
            var random = new Random(seed);
            float randomFloat() => (float)(random.NextDouble() - 0.5);
            for (int i = 0; i < count; i++)
            {
                // Generate Labels that are integers 1, 2 or 3
                var label = random.Next(1, 4);
                yield return new DataPoint
                {
                    Label = (uint)label,
                    // Create random features that are correlated with the label.
                    // The feature values are slightly increased by adding a
                    // constant multiple of label.
                    Features = Enumerable.Repeat(label, 20)
                        .Select(x => randomFloat() + label * 0.2f).ToArray()

                };
            }
        }

        // Example with label and 20 feature values. A data set is a collection of
        // such examples.
        private class DataPoint
        {
            public uint Label { get; set; }
            [VectorType(20)]
            public float[] Features { get; set; }
        }

        // Class used to capture predictions.
        private class Prediction
        {
            // Original label.
            public uint Label { get; set; }
            // Predicted label from the trainer.
            public uint PredictedLabel { get; set; }
        }

        // Pretty-print MulticlassClassificationMetrics objects.
        public static void PrintMetrics(MulticlassClassificationMetrics metrics)
        {
            Console.WriteLine($"Micro Accuracy: {metrics.MicroAccuracy:F2}");
            Console.WriteLine($"Macro Accuracy: {metrics.MacroAccuracy:F2}");
            Console.WriteLine($"Log Loss: {metrics.LogLoss:F2}");
            Console.WriteLine(
                $"Log Loss Reduction: {metrics.LogLossReduction:F2}\n");

            Console.WriteLine(metrics.ConfusionMatrix.GetFormattedConfusionTable());
        }
    }
}

S’applique à

LbfgsMaximumEntropy(MulticlassClassificationCatalog+MulticlassClassificationTrainers, String, String, String, Single, Single, Single, Int32, Boolean)

Créez LbfgsMaximumEntropyMulticlassTrainer, qui prédit une cible à l’aide d’un modèle de classification d’entropie maximal entraîné avec la méthode L-BFGS.

public static Microsoft.ML.Trainers.LbfgsMaximumEntropyMulticlassTrainer LbfgsMaximumEntropy (this Microsoft.ML.MulticlassClassificationCatalog.MulticlassClassificationTrainers catalog, string labelColumnName = "Label", string featureColumnName = "Features", string exampleWeightColumnName = default, float l1Regularization = 1, float l2Regularization = 1, float optimizationTolerance = 1E-07, int historySize = 20, bool enforceNonNegativity = false);
static member LbfgsMaximumEntropy : Microsoft.ML.MulticlassClassificationCatalog.MulticlassClassificationTrainers * string * string * string * single * single * single * int * bool -> Microsoft.ML.Trainers.LbfgsMaximumEntropyMulticlassTrainer
<Extension()>
Public Function LbfgsMaximumEntropy (catalog As MulticlassClassificationCatalog.MulticlassClassificationTrainers, Optional labelColumnName As String = "Label", Optional featureColumnName As String = "Features", Optional exampleWeightColumnName As String = Nothing, Optional l1Regularization As Single = 1, Optional l2Regularization As Single = 1, Optional optimizationTolerance As Single = 1E-07, Optional historySize As Integer = 20, Optional enforceNonNegativity As Boolean = false) As LbfgsMaximumEntropyMulticlassTrainer

Paramètres

catalog
MulticlassClassificationCatalog.MulticlassClassificationTrainers

Le MulticlassClassificationCatalog.MulticlassClassificationTrainers.

labelColumnName
String

Nom de la colonne d’étiquette. Les données de colonne doivent être KeyDataViewType.

featureColumnName
String

Nom de la colonne de fonctionnalité. Les données de colonne doivent être un vecteur de taille connue de Single.

exampleWeightColumnName
String

Nom de l’exemple de colonne de poids (facultatif).

l1Regularization
Single

Hyperparamètre de régularisation L1. Les valeurs plus élevées ont tendance à entraîner un modèle plus épars.

l2Regularization
Single

Poids L2 pour la régularisation.

optimizationTolerance
Single

Seuil de convergence de l’optimiseur.

historySize
Int32

Taille de la mémoire pour LbfgsMaximumEntropyMulticlassTrainer. Low=faster, moins précis.

enforceNonNegativity
Boolean

Appliquer des pondérations non négatives.

Retours

LbfgsMaximumEntropyMulticlassTrainer

Exemples

using System;
using System.Collections.Generic;
using System.Linq;
using Microsoft.ML;
using Microsoft.ML.Data;

namespace Samples.Dynamic.Trainers.MulticlassClassification
{
    public static class LbfgsMaximumEntropy
    {
        public static void Example()
        {
            // Create a new context for ML.NET operations. It can be used for
            // exception tracking and logging, as a catalog of available operations
            // and as the source of randomness. Setting the seed to a fixed number
            // in this example to make outputs deterministic.
            var mlContext = new MLContext(seed: 0);

            // Create a list of training data points.
            var dataPoints = GenerateRandomDataPoints(1000);

            // Convert the list of data points to an IDataView object, which is
            // consumable by ML.NET API.
            var trainingData = mlContext.Data.LoadFromEnumerable(dataPoints);

            // Define the trainer.
            var pipeline =
                // Convert the string labels into key types.
                mlContext.Transforms.Conversion
                .MapValueToKey(nameof(DataPoint.Label))
                // Apply LbfgsMaximumEntropy multiclass trainer.
                .Append(mlContext.MulticlassClassification.Trainers
                .LbfgsMaximumEntropy());

            // Train the model.
            var model = pipeline.Fit(trainingData);

            // Create testing data. Use different random seed to make it different
            // from training data.
            var testData = mlContext.Data
                .LoadFromEnumerable(GenerateRandomDataPoints(500, seed: 123));

            // Run the model on test data set.
            var transformedTestData = model.Transform(testData);

            // Convert IDataView object to a list.
            var predictions = mlContext.Data
                .CreateEnumerable<Prediction>(transformedTestData,
                reuseRowObject: false).ToList();

            // Look at 5 predictions
            foreach (var p in predictions.Take(5))
                Console.WriteLine($"Label: {p.Label}, " +
                    $"Prediction: {p.PredictedLabel}");

            // Expected output:
            //   Label: 1, Prediction: 1
            //   Label: 2, Prediction: 2
            //   Label: 3, Prediction: 2
            //   Label: 2, Prediction: 2
            //   Label: 3, Prediction: 3

            // Evaluate the overall metrics
            var metrics = mlContext.MulticlassClassification
                .Evaluate(transformedTestData);

            PrintMetrics(metrics);

            // Expected output:
            //  Micro Accuracy: 0.91
            //  Macro Accuracy: 0.91
            //  Log Loss: 0.24
            //  Log Loss Reduction: 0.79

            //  Confusion table
            //            ||========================
            //  PREDICTED ||     0 |     1 |     2 | Recall
            //  TRUTH     ||========================
            //          0 ||   148 |     0 |    12 | 0.9250
            //          1 ||     0 |   165 |    12 | 0.9322
            //          2 ||    11 |     7 |   145 | 0.8896
            //            ||========================
            //  Precision ||0.9308 |0.9593 |0.8580 |
        }

        // Generates random uniform doubles in [-0.5, 0.5)
        // range with labels 1, 2 or 3.
        private static IEnumerable<DataPoint> GenerateRandomDataPoints(int count,
            int seed = 0)

        {
            var random = new Random(seed);
            float randomFloat() => (float)(random.NextDouble() - 0.5);
            for (int i = 0; i < count; i++)
            {
                // Generate Labels that are integers 1, 2 or 3
                var label = random.Next(1, 4);
                yield return new DataPoint
                {
                    Label = (uint)label,
                    // Create random features that are correlated with the label.
                    // The feature values are slightly increased by adding a
                    // constant multiple of label.
                    Features = Enumerable.Repeat(label, 20)
                        .Select(x => randomFloat() + label * 0.2f).ToArray()

                };
            }
        }

        // Example with label and 20 feature values. A data set is a collection of
        // such examples.
        private class DataPoint
        {
            public uint Label { get; set; }
            [VectorType(20)]
            public float[] Features { get; set; }
        }

        // Class used to capture predictions.
        private class Prediction
        {
            // Original label.
            public uint Label { get; set; }
            // Predicted label from the trainer.
            public uint PredictedLabel { get; set; }
        }

        // Pretty-print MulticlassClassificationMetrics objects.
        public static void PrintMetrics(MulticlassClassificationMetrics metrics)
        {
            Console.WriteLine($"Micro Accuracy: {metrics.MicroAccuracy:F2}");
            Console.WriteLine($"Macro Accuracy: {metrics.MacroAccuracy:F2}");
            Console.WriteLine($"Log Loss: {metrics.LogLoss:F2}");
            Console.WriteLine(
                $"Log Loss Reduction: {metrics.LogLossReduction:F2}\n");

            Console.WriteLine(metrics.ConfusionMatrix.GetFormattedConfusionTable());
        }
    }
}

S’applique à