NormalizationCatalog.NormalizeMeanVariance Méthode

Définition

Espace de noms:

Microsoft.ML

Assembly:

Microsoft.ML.Transforms.dll

Paquet:

Microsoft.ML v2.0.0

Surcharges

NormalizeMeanVariance(TransformsCatalog, InputOutputColumnPair[], Int64, Boolean, Boolean)	Créez un NormalizingEstimator, qui normalise en fonction de la moyenne calculée et de la variance des données.
NormalizeMeanVariance(TransformsCatalog, String, String, Int64, Boolean, Boolean)	Créez un NormalizingEstimator, qui normalise en fonction de la moyenne calculée et de la variance des données.

NormalizeMeanVariance(TransformsCatalog, InputOutputColumnPair[], Int64, Boolean, Boolean)

Créez un NormalizingEstimator, qui normalise en fonction de la moyenne calculée et de la variance des données.

public static Microsoft.ML.Transforms.NormalizingEstimator NormalizeMeanVariance (this Microsoft.ML.TransformsCatalog catalog, Microsoft.ML.InputOutputColumnPair[] columns, long maximumExampleCount = 1000000000, bool fixZero = true, bool useCdf = false);

static member NormalizeMeanVariance : Microsoft.ML.TransformsCatalog * Microsoft.ML.InputOutputColumnPair[] * int64 * bool * bool -> Microsoft.ML.Transforms.NormalizingEstimator

<Extension()>
Public Function NormalizeMeanVariance (catalog As TransformsCatalog, columns As InputOutputColumnPair(), Optional maximumExampleCount As Long = 1000000000, Optional fixZero As Boolean = true, Optional useCdf As Boolean = false) As NormalizingEstimator

Paramètres

catalog

TransformsCatalog

Catalogue de transformations

columns

InputOutputColumnPair[]

Paires de colonnes d’entrée et de sortie. Les colonnes d’entrée doivent être de type Singlede données ou Double un vecteur de taille connue de ces types. Le type de données de la colonne de sortie sera identique à la colonne d’entrée associée.

maximumExampleCount

Int64

Nombre maximal d’exemples utilisés pour entraîner le normaliseur.

fixZero

Boolean

Indique s’il faut mapper zéro à zéro, en préservant l’éparse.

useCdf

Boolean

Indique s’il faut utiliser la CDF comme sortie.

Retours

NormalizingEstimator

NormalizeMeanVariance(TransformsCatalog, String, String, Int64, Boolean, Boolean)

Créez un NormalizingEstimator, qui normalise en fonction de la moyenne calculée et de la variance des données.

public static Microsoft.ML.Transforms.NormalizingEstimator NormalizeMeanVariance (this Microsoft.ML.TransformsCatalog catalog, string outputColumnName, string inputColumnName = default, long maximumExampleCount = 1000000000, bool fixZero = true, bool useCdf = false);

static member NormalizeMeanVariance : Microsoft.ML.TransformsCatalog * string * string * int64 * bool * bool -> Microsoft.ML.Transforms.NormalizingEstimator

<Extension()>
Public Function NormalizeMeanVariance (catalog As TransformsCatalog, outputColumnName As String, Optional inputColumnName As String = Nothing, Optional maximumExampleCount As Long = 1000000000, Optional fixZero As Boolean = true, Optional useCdf As Boolean = false) As NormalizingEstimator

Paramètres

catalog

TransformsCatalog

Catalogue de transformations

outputColumnName

String

Nom de la colonne résultant de la transformation de inputColumnName. Le type de données de cette colonne est identique à la colonne d’entrée.

inputColumnName

String

Nom de la colonne à transformer. Si la valeur est définie null, la valeur du outputColumnName fichier sera utilisée comme source. Le type de données de cette colonne doit être Single, Double ou un vecteur de taille connue de ces types.

maximumExampleCount

Int64

Nombre maximal d’exemples utilisés pour entraîner le normaliseur.

fixZero

Boolean

Indique s’il faut mapper zéro à zéro, en préservant l’éparse.

useCdf

Boolean

Indique s’il faut utiliser la CDF comme sortie.

Retours

NormalizingEstimator

Exemples

using System;
using System.Collections.Generic;
using System.Collections.Immutable;
using System.Linq;
using Microsoft.ML;
using Microsoft.ML.Data;
using static Microsoft.ML.Transforms.NormalizingTransformer;

namespace Samples.Dynamic
{
    public class NormalizeMeanVariance
    {
        public static void Example()
        {
            // Create a new ML context, for ML.NET operations. It can be used for
            // exception tracking and logging, as well as the source of randomness.
            var mlContext = new MLContext();
            var samples = new List<DataPoint>()
            {
                new DataPoint(){ Features = new float[4] { 1, 1, 3, 0} },
                new DataPoint(){ Features = new float[4] { 2, 2, 2, 0} },
                new DataPoint(){ Features = new float[4] { 0, 0, 1, 0} },
                new DataPoint(){ Features = new float[4] {-1,-1,-1, 1} }
            };
            // Convert training data to IDataView, the general data type used in
            // ML.NET.
            var data = mlContext.Data.LoadFromEnumerable(samples);
            // NormalizeMeanVariance normalizes the data based on the computed mean
            // and variance of the data. Uses Cumulative distribution function as
            // output.
            var normalize = mlContext.Transforms.NormalizeMeanVariance("Features",
                useCdf: true);

            // NormalizeMeanVariance normalizes the data based on the computed mean
            // and variance of the data.
            var normalizeNoCdf = mlContext.Transforms.NormalizeMeanVariance(
                "Features", useCdf: false);

            // Now we can transform the data and look at the output to confirm the
            // behavior of the estimator. This operation doesn't actually evaluate
            // data until we read the data below.
            var normalizeTransform = normalize.Fit(data);
            var transformedData = normalizeTransform.Transform(data);
            var normalizeNoCdfTransform = normalizeNoCdf.Fit(data);
            var noCdfData = normalizeNoCdfTransform.Transform(data);
            var column = transformedData.GetColumn<float[]>("Features").ToArray();
            foreach (var row in column)
                Console.WriteLine(string.Join(", ", row.Select(x => x.ToString(
                    "f4"))));
            // Expected output:
            //  0.6726, 0.6726, 0.8816, 0.2819
            //  0.9101, 0.9101, 0.6939, 0.2819
            //  0.3274, 0.3274, 0.4329, 0.2819
            //  0.0899, 0.0899, 0.0641, 0.9584


            var columnFixZero = noCdfData.GetColumn<float[]>("Features").ToArray();
            foreach (var row in columnFixZero)
                Console.WriteLine(string.Join(", ", row.Select(x => x.ToString(
                    "f4"))));
            // Expected output:
            //  0.8165, 0.8165, 1.5492, 0.0000
            //  1.6330, 1.6330, 1.0328, 0.0000
            //  0.0000, 0.0000, 0.5164, 0.0000
            // -0.8165,-0.8165,-0.5164, 2.0000

            // Let's get transformation parameters. Since we work with only one
            // column we need to pass 0 as parameter for
            // GetNormalizerModelParameters. If we have multiple columns
            // transformations we need to pass index of InputOutputColumnPair.
            var transformParams = normalizeTransform
                .GetNormalizerModelParameters(0) as CdfNormalizerModelParameters<
                ImmutableArray<float>>;

            Console.WriteLine($"The 1-index value in resulting array would " +
                $"be produce by:");

            Console.WriteLine(" y = 0.5* (1 + ERF((x- " + transformParams.Mean[1] +
                ") / (" + transformParams.StandardDeviation[1] + " * sqrt(2)))");
            // ERF is https://en.wikipedia.org/wiki/Error_function.
            // Expected output:
            //  The 1-index value in resulting array would be produce by:
            //  y = 0.5 * (1 + ERF((x - 0.5) / (1.118034 * sqrt(2)))

            var noCdfParams = normalizeNoCdfTransform
                .GetNormalizerModelParameters(0) as
                AffineNormalizerModelParameters<ImmutableArray<float>>;

            var offset = noCdfParams.Offset.Length == 0 ? 0 : noCdfParams.Offset[1];
            var scale = noCdfParams.Scale[1];
            Console.WriteLine($"Values for slot 1 would be transformed by " +
                $"applying y = (x - ({offset})) * {scale}");
            // Expected output:
            // The 1-index value in resulting array would be produce by: y = (x - (0)) * 0.8164966
        }

        private class DataPoint
        {
            [VectorType(4)]
            public float[] Features { get; set; }
        }
    }
}