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FeatureSelectionCatalog.SelectFeaturesBasedOnCount Método

Definição

Sobrecargas

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

Crie um CountFeatureSelectingEstimator, que seleciona os slots para os quais a contagem de valores não padrão é maior ou igual a um limite.

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

Crie um CountFeatureSelectingEstimator, que seleciona os slots para os quais a contagem de valores não padrão é maior ou igual a um limite.

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

Crie um CountFeatureSelectingEstimator, que seleciona os slots para os quais a contagem de valores não padrão é maior ou igual a um limite.

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

Parâmetros

catalog
TransformsCatalog.FeatureSelectionTransforms

O catálogo da transformação.

columns
InputOutputColumnPair[]

Especifica os nomes das colunas nas quais aplicar a transformação. Esse avaliador opera por vetor ou escalar de tipos de dados numéricos, de texto ou de chaves. Os tipos de dados das colunas de saída serão iguais aos tipos de dados das colunas de entrada.

count
Int64

Se a contagem de valores não padrão para um slot for maior ou igual a esse limite nos dados de treinamento, o slot será preservado.

Retornos

Exemplos

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;
        }
    }
}

Aplica-se a

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

Crie um CountFeatureSelectingEstimator, que seleciona os slots para os quais a contagem de valores não padrão é maior ou igual a um limite.

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

Parâmetros

catalog
TransformsCatalog.FeatureSelectionTransforms

O catálogo da transformação.

outputColumnName
String

Nome da coluna resultante da transformação de inputColumnName. O tipo de dados desta coluna será o mesmo que o tipo de dados da coluna de entrada.

inputColumnName
String

Nome da coluna a ser transformada. Se definido como null, o valor do outputColumnName será usado como origem. Esse avaliador opera por vetor ou escalar de tipos de dados numéricos, de texto ou de chaves.

count
Int64

Se a contagem de valores não padrão para um slot for maior ou igual a esse limite nos dados de treinamento, o slot será preservado.

Retornos

Exemplos

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;
        }
    }
}

Aplica-se a