NormalizationCatalog.NormalizeMinMax Metodo

Definizione

Spazio dei nomi:

Microsoft.ML

Assembly:

Microsoft.ML.Transforms.dll

Pacchetto:

Microsoft.ML v2.0.0

Overload

NormalizeMinMax(TransformsCatalog, InputOutputColumnPair[], Int64, Boolean)	Creare un NormalizingEstimatoroggetto , che normalizza in base ai valori minimi e massimi osservati dei dati.
NormalizeMinMax(TransformsCatalog, String, String, Int64, Boolean)	Creare un NormalizingEstimatoroggetto , che normalizza in base ai valori minimi e massimi osservati dei dati.

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

Creare un NormalizingEstimatoroggetto , che normalizza in base ai valori minimi e massimi osservati dei dati.

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

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

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

Parametri

catalog

TransformsCatalog

Catalogo di trasformazione

columns

InputOutputColumnPair[]

Coppie di colonne di input e di output. Le colonne di input devono essere di tipo SingleDouble di dati o un vettore di dimensioni note di tali tipi. Il tipo di dati per la colonna di output sarà uguale alla colonna di input associata.

maximumExampleCount

Int64

Numero massimo di esempi usati per eseguire il training del normalizzatore.

fixZero

Boolean

Indica se eseguire il mapping di zero a zero, mantenendo la spaziatura.

Restituisce

NormalizingEstimator

Esempio

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
{
    class NormalizeMinMaxMulticolumn
    {
        public static void Example()
        {
            var mlContext = new MLContext();
            var samples = new List<DataPoint>()
            {
                new DataPoint()
                {
                    Features = new float[4] { 1, 1, 3, 0 },
                    Features2 = new float[3] { 1, 2, 3 }
                },
                new DataPoint()
                {
                    Features = new float[4] { 2, 2, 2, 0 },
                    Features2 = new float[3] { 3, 4, 5 }
                },
                new DataPoint()
                {
                    Features = new float[4] { 0, 0, 1, 0 },
                    Features2 = new float[3] { 6, 7, 8 }
                },
                new DataPoint()
                {
                    Features = new float[4] {-1,-1,-1, 1 },
                    Features2 = new float[3] { 9, 0, 4 }
                }
            };

            // Convert training data to IDataView, the general data type used in
            // ML.NET.
            var data = mlContext.Data.LoadFromEnumerable(samples);

            var columnPair = new[]
            {
                new InputOutputColumnPair("Features"),
                new InputOutputColumnPair("Features2")
            };

            // NormalizeMinMax normalize rows by finding min and max values in each
            // row slot and setting projection of min value to 0 and max to 1 and
            // everything else to values in between.
            var normalize = mlContext.Transforms.NormalizeMinMax(columnPair,
                fixZero: false);

            // Normalize rows by finding min and max values in each row slot, but
            // make sure zero values remain zero after normalization. Helps
            // preserve sparsity. That is, to help maintain very little non-zero elements.
            var normalizeFixZero = mlContext.Transforms.NormalizeMinMax(columnPair,
                fixZero: true);

            // 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 normalizeFixZeroTransform = normalizeFixZero.Fit(data);
            var fixZeroData = normalizeFixZeroTransform.Transform(data);
            var column = transformedData.GetColumn<float[]>("Features").ToArray();
            var column2 = transformedData.GetColumn<float[]>("Features2").ToArray();

            for (int i = 0; i < column.Length; i++)
                Console.WriteLine(string.Join(", ", column[i].Select(x => x
                .ToString("f4"))) + "\t\t" +
                string.Join(", ", column2[i].Select(x => x.ToString("f4"))));

            // Expected output:
            // Features                                Features2  
            // 0.6667, 0.6667, 1.0000, 0.0000          0.0000, 0.2857, 0.0000
            // 1.0000, 1.0000, 0.7500, 0.0000          0.2500, 0.5714, 0.4000
            // 0.3333, 0.3333, 0.5000, 0.0000          0.6250, 1.0000, 1.0000
            // 0.0000, 0.0000, 0.0000, 1.0000          1.0000, 0.0000, 0.2000

            var columnFixZero = fixZeroData.GetColumn<float[]>("Features").ToArray();
            var column2FixZero = fixZeroData.GetColumn<float[]>("Features2").ToArray();

            Console.WriteLine(Environment.NewLine);

            for (int i = 0; i < column.Length; i++)
                Console.WriteLine(string.Join(", ", columnFixZero[i].Select(x => x
                .ToString("f4"))) + "\t\t" +
                string.Join(", ", column2FixZero[i].Select(x => x.ToString("f4"))));

            // Expected output:
            // Features                                Features2  
            // 0.5000, 0.5000, 1.0000, 0.0000          0.1111, 0.2857, 0.3750
            // 1.0000, 1.0000, 0.6667, 0.0000          0.3333, 0.5714, 0.6250
            // 0.0000, 0.0000, 0.3333, 0.0000          0.6667, 1.0000, 1.0000
            // -0.5000, -0.5000, -0.3333, 1.0000       1.0000, 0.0000, 0.5000

            // Get transformation parameters. Since we have multiple columns
            // we need to pass index of InputOutputColumnPair.
            var transformParams = normalizeTransform.GetNormalizerModelParameters(0)
                as AffineNormalizerModelParameters<ImmutableArray<float>>;

            var transformParams2 = normalizeTransform.GetNormalizerModelParameters(1)
                as AffineNormalizerModelParameters<ImmutableArray<float>>;

            Console.WriteLine(Environment.NewLine);

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

            Console.WriteLine(" y = (x - (" + (transformParams.Offset.Length == 0 ?
                0 : transformParams.Offset[1]) + ")) * " + transformParams
                .Scale[1]);

            // Expected output:
            //  The 1-index value in resulting array would be produce by:
            //  y = (x - (-1)) * 0.3333333
        }

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

            [VectorType(3)]
            public float[] Features2 { get; set; }
        }
    }
}

NormalizeMinMax(TransformsCatalog, String, String, Int64, Boolean)

Creare un NormalizingEstimatoroggetto , che normalizza in base ai valori minimi e massimi osservati dei dati.

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

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

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

Parametri

catalog

TransformsCatalog

Catalogo di trasformazione

outputColumnName

String

Nome della colonna risultante dalla trasformazione di inputColumnName. Il tipo di dati in questa colonna corrisponde alla colonna di input.

inputColumnName

String

Nome della colonna da trasformare. Se impostato su null, il valore di outputColumnName verrà usato come origine. Il tipo di dati in questa colonna deve essere Singleo Double un vettore di dimensioni note di tali tipi.

maximumExampleCount

Int64

Numero massimo di esempi usati per eseguire il training del normalizzatore.

fixZero

Boolean

Indica se eseguire il mapping di zero a zero, mantenendo la spaziatura.

Restituisce

NormalizingEstimator

Esempio

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 NormalizeMinMax
    {
        public static void Example()
        {
            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);
            // NormalizeMinMax normalize rows by finding min and max values in each
            // row slot and setting projection of min value to 0 and max to 1 and
            // everything else to values in between.
            var normalize = mlContext.Transforms.NormalizeMinMax("Features",
                fixZero: false);

            // Normalize rows by finding min and max values in each row slot, but
            // make sure zero values remain zero after normalization. Helps
            // preserve sparsity. That is, to help maintain very little non-zero elements.
            var normalizeFixZero = mlContext.Transforms.NormalizeMinMax("Features",
                fixZero: true);

            // 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 normalizeFixZeroTransform = normalizeFixZero.Fit(data);
            var fixZeroData = normalizeFixZeroTransform.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:
            //  0.6667, 0.6667, 1.0000, 0.0000
            //  1.0000, 1.0000, 0.7500, 0.0000
            //  0.3333, 0.3333, 0.5000, 0.0000
            //  0.0000, 0.0000, 0.0000, 1.0000

            var columnFixZero = fixZeroData.GetColumn<float[]>("Features")
                .ToArray();

            foreach (var row in columnFixZero)
                Console.WriteLine(string.Join(", ", row.Select(x => x.ToString(
                    "f4"))));
            // Expected output:
            //  0.5000, 0.5000, 1.0000, 0.0000
            //  1.0000, 1.0000, 0.6667, 0.0000
            //  0.0000, 0.0000, 0.3333, 0.0000
            // -0.5000,-0.5000,-0.3333, 1.0000

            // 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 AffineNormalizerModelParameters<ImmutableArray<float>>;

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

            Console.WriteLine(" y = (x - (" + (transformParams.Offset.Length == 0 ?
                0 : transformParams.Offset[1]) + ")) * " + transformParams
                .Scale[1]);
            // Expected output:
            //  The 1-index value in resulting array would be produce by: 
            //  y = (x - (-1)) * 0.3333333
        }

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