FeatureSelectionCatalog.SelectFeaturesBasedOnCount Método

Definición

Espacio de nombres:

Microsoft.ML

Ensamblado:

Microsoft.ML.Transforms.dll

Paquete:

Microsoft.ML v2.0.0

Sobrecargas

SelectFeaturesBasedOnCount(TransformsCatalog+FeatureSelectionTransforms, InputOutputColumnPair[], Int64)	Cree un CountFeatureSelectingEstimator, que seleccione las ranuras para las que el recuento de valores no predeterminados es mayor o igual que un umbral.
SelectFeaturesBasedOnCount(TransformsCatalog+FeatureSelectionTransforms, String, String, Int64)	Cree un CountFeatureSelectingEstimator, que seleccione las ranuras para las que el recuento de valores no predeterminados es mayor o igual que un umbral.

SelectFeaturesBasedOnCount(TransformsCatalog+FeatureSelectionTransforms, InputOutputColumnPair[], Int64)

Cree un CountFeatureSelectingEstimator, que seleccione las ranuras para las que el recuento de valores no predeterminados es mayor o igual que un umbral.

public static Microsoft.ML.Transforms.CountFeatureSelectingEstimator SelectFeaturesBasedOnCount (this Microsoft.ML.TransformsCatalog.FeatureSelectionTransforms catalog, Microsoft.ML.InputOutputColumnPair[] columns, long count = 1);

static member SelectFeaturesBasedOnCount : Microsoft.ML.TransformsCatalog.FeatureSelectionTransforms * Microsoft.ML.InputOutputColumnPair[] * int64 -> Microsoft.ML.Transforms.CountFeatureSelectingEstimator

<Extension()>
Public Function SelectFeaturesBasedOnCount (catalog As TransformsCatalog.FeatureSelectionTransforms, columns As InputOutputColumnPair(), Optional count As Long = 1) As CountFeatureSelectingEstimator

Parámetros

catalog

TransformsCatalog.FeatureSelectionTransforms

Catálogo de la transformación.

columns

InputOutputColumnPair[]

Especifica los nombres de las columnas en las que se va a aplicar la transformación. Este estimador opera sobre el vector o escalar de tipos de datos numéricos, de texto o de claves. Los tipos de datos de las columnas de salida serán los mismos que los tipos de datos de las columnas de entrada.

count

Int64

Si el recuento de valores no predeterminados para una ranura es mayor o igual que este umbral en los datos de entrenamiento, se conserva la ranura.

Devoluciones

CountFeatureSelectingEstimator

Ejemplos

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

namespace Samples.Dynamic
{
    public static class SelectFeaturesBasedOnCountMultiColumn
    {
        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();

            // Get a small dataset as an IEnumerable and convert it to an IDataView.
            var rawData = GetData();

            // Printing the columns of the input data. 
            Console.WriteLine($"NumericVector             StringVector");
            foreach (var item in rawData)
                Console.WriteLine("{0,-25} {1,-25}", string.Join(",", item.
                    NumericVector), string.Join(",", item.StringVector));

            // NumericVector             StringVector
            // 4,NaN,6                   A,WA,Male
            // 4,5,6                     A,,Female
            // 4,5,6                     A,NY,
            // 4,NaN,NaN                 A,,Male

            var data = mlContext.Data.LoadFromEnumerable(rawData);

            // We will use the SelectFeaturesBasedOnCount transform estimator, to
            // retain only those slots which have at least 'count' non-default
            // values per slot.

            // Multi column example. This pipeline transform two columns using the
            // provided parameters.
            var pipeline = mlContext.Transforms.FeatureSelection
                .SelectFeaturesBasedOnCount(new InputOutputColumnPair[] { new
                InputOutputColumnPair("NumericVector"), new InputOutputColumnPair(
                "StringVector") }, count: 3);

            var transformedData = pipeline.Fit(data).Transform(data);

            var convertedData = mlContext.Data.CreateEnumerable<TransformedData>(
                transformedData, true);

            // Printing the columns of the transformed data. 
            Console.WriteLine($"NumericVector             StringVector");
            foreach (var item in convertedData)
                Console.WriteLine("{0,-25} {1,-25}", string.Join(",", item
                    .NumericVector), string.Join(",", item.StringVector));

            // NumericVector             StringVector
            // 4,6                       A,Male
            // 4,6                       A,Female
            // 4,6                       A,
            // 4,NaN                     A,Male
        }

        private class TransformedData
        {
            public float[] NumericVector { get; set; }

            public string[] StringVector { get; set; }
        }

        public class InputData
        {
            [VectorType(3)]
            public float[] NumericVector { get; set; }

            [VectorType(3)]
            public string[] StringVector { get; set; }
        }

        /// <summary>
        /// Returns a few rows of data.
        /// </summary>
        public static IEnumerable<InputData> GetData()
        {
            var data = new List<InputData>
            {
                new InputData
                {
                    NumericVector = new float[] { 4, float.NaN, 6 },
                    StringVector = new string[] { "A", "WA", "Male"}
                },
                new InputData
                {
                    NumericVector = new float[] { 4, 5, 6 },
                    StringVector = new string[] { "A", "", "Female"}
                },
                new InputData
                {
                    NumericVector = new float[] { 4, 5, 6 },
                    StringVector = new string[] { "A", "NY", null}
                },
                new InputData
                {
                    NumericVector = new float[] { 4, float.NaN, float.NaN },
                    StringVector = new string[] { "A", null, "Male"}
                }
            };
            return data;
        }
    }
}

SelectFeaturesBasedOnCount(TransformsCatalog+FeatureSelectionTransforms, String, String, Int64)

Cree un CountFeatureSelectingEstimator, que seleccione las ranuras para las que el recuento de valores no predeterminados es mayor o igual que un umbral.

public static Microsoft.ML.Transforms.CountFeatureSelectingEstimator SelectFeaturesBasedOnCount (this Microsoft.ML.TransformsCatalog.FeatureSelectionTransforms catalog, string outputColumnName, string inputColumnName = default, long count = 1);

static member SelectFeaturesBasedOnCount : Microsoft.ML.TransformsCatalog.FeatureSelectionTransforms * string * string * int64 -> Microsoft.ML.Transforms.CountFeatureSelectingEstimator

<Extension()>
Public Function SelectFeaturesBasedOnCount (catalog As TransformsCatalog.FeatureSelectionTransforms, outputColumnName As String, Optional inputColumnName As String = Nothing, Optional count As Long = 1) As CountFeatureSelectingEstimator

Parámetros

catalog

TransformsCatalog.FeatureSelectionTransforms

Catálogo de la transformación.

outputColumnName

String

Nombre de la columna resultante de la transformación de inputColumnName. El tipo de datos de esta columna será el mismo que el tipo de datos de la columna de entrada.

inputColumnName

String

Nombre de la columna que se va a transformar. Si se establece nullen , el valor de outputColumnName se usará como origen. Este estimador opera sobre el vector o escalar de tipos de datos numéricos, de texto o de claves.

count

Int64

Si el recuento de valores no predeterminados para una ranura es mayor o igual que este umbral en los datos de entrenamiento, se conserva la ranura.

Devoluciones

CountFeatureSelectingEstimator

Ejemplos

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

namespace Samples.Dynamic
{
    public static class SelectFeaturesBasedOnCount
    {
        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();

            // Get a small dataset as an IEnumerable and convert it to an IDataView.
            var rawData = GetData();

            // Printing the columns of the input data. 
            Console.WriteLine($"NumericVector             StringVector");
            foreach (var item in rawData)
                Console.WriteLine("{0,-25} {1,-25}", string.Join(",", item
                    .NumericVector), string.Join(",", item.StringVector));

            // NumericVector             StringVector
            // 4,NaN,6                   A,WA,Male
            // 4,5,6                     A,,Female
            // 4,5,6                     A,NY,
            // 4,0,NaN                   A,,Male

            var data = mlContext.Data.LoadFromEnumerable(rawData);

            // We will use the SelectFeaturesBasedOnCount to retain only those slots
            // which have at least 'count' non-default and non-missing values per
            // slot.
            var pipeline =
                mlContext.Transforms.FeatureSelection.SelectFeaturesBasedOnCount(
                    outputColumnName: "NumericVector", count: 3) // Usage on numeric 
                                                                 // column.
                .Append(mlContext.Transforms.FeatureSelection
                .SelectFeaturesBasedOnCount(outputColumnName: "StringVector",
                count: 3)); // Usage on text column.

            var transformedData = pipeline.Fit(data).Transform(data);

            var convertedData = mlContext.Data.CreateEnumerable<TransformedData>(
                transformedData, true);

            // Printing the columns of the transformed data. 
            Console.WriteLine($"NumericVector             StringVector");
            foreach (var item in convertedData)
                Console.WriteLine("{0,-25} {1,-25}", string.Join(",", item.
                    NumericVector), string.Join(",", item.StringVector));

            // NumericVector             StringVector
            // 4,6                       A,Male
            // 4,6                       A,Female
            // 4,6                       A,
            // 4,NaN                     A,Male
        }

        public class TransformedData
        {
            public float[] NumericVector { get; set; }

            public string[] StringVector { get; set; }
        }

        public class InputData
        {
            [VectorType(3)]
            public float[] NumericVector { get; set; }

            [VectorType(3)]
            public string[] StringVector { get; set; }
        }

        /// <summary>
        /// Return a few rows of data.
        /// </summary>
        public static IEnumerable<InputData> GetData()
        {
            var data = new List<InputData>
            {
                new InputData
                {
                    NumericVector = new float[] { 4, float.NaN, 6 },
                    StringVector = new string[] { "A", "WA", "Male"}
                },
                new InputData
                {
                    NumericVector = new float[] { 4, 5, 6 },
                    StringVector = new string[] { "A", string.Empty, "Female"}
                },
                new InputData
                {
                    NumericVector = new float[] { 4, 5, 6 },
                    StringVector = new string[] { "A", "NY", null}
                },
                new InputData
                {
                    NumericVector = new float[] { 4, 0, float.NaN },
                    StringVector = new string[] { "A", null, "Male"}
                }
            };
            return data;
        }
    }
}