ConversionsExtensionsCatalog.MapValueToKey Metodo

Definizione

Spazio dei nomi:

Microsoft.ML

Assembly:

Microsoft.ML.Data.dll

Pacchetto:

Microsoft.ML v2.0.0

Overload

MapValueToKey(TransformsCatalog+ConversionTransforms, InputOutputColumnPair[], Int32, ValueToKeyMappingEstimator+KeyOrdinality, Boolean, IDataView)	Creare un ValueToKeyMappingEstimatoroggetto , che converte i valori categorici in chiavi.
MapValueToKey(TransformsCatalog+ConversionTransforms, String, String, Int32, ValueToKeyMappingEstimator+KeyOrdinality, Boolean, IDataView)	Creare un ValueToKeyMappingEstimatoroggetto , che converte i valori categorici in chiavi numeriche.

MapValueToKey(TransformsCatalog+ConversionTransforms, InputOutputColumnPair[], Int32, ValueToKeyMappingEstimator+KeyOrdinality, Boolean, IDataView)

Creare un ValueToKeyMappingEstimatoroggetto , che converte i valori categorici in chiavi.

public static Microsoft.ML.Transforms.ValueToKeyMappingEstimator MapValueToKey (this Microsoft.ML.TransformsCatalog.ConversionTransforms catalog, Microsoft.ML.InputOutputColumnPair[] columns, int maximumNumberOfKeys = 1000000, Microsoft.ML.Transforms.ValueToKeyMappingEstimator.KeyOrdinality keyOrdinality = Microsoft.ML.Transforms.ValueToKeyMappingEstimator+KeyOrdinality.ByOccurrence, bool addKeyValueAnnotationsAsText = false, Microsoft.ML.IDataView keyData = default);

static member MapValueToKey : Microsoft.ML.TransformsCatalog.ConversionTransforms * Microsoft.ML.InputOutputColumnPair[] * int * Microsoft.ML.Transforms.ValueToKeyMappingEstimator.KeyOrdinality * bool * Microsoft.ML.IDataView -> Microsoft.ML.Transforms.ValueToKeyMappingEstimator

<Extension()>
Public Function MapValueToKey (catalog As TransformsCatalog.ConversionTransforms, columns As InputOutputColumnPair(), Optional maximumNumberOfKeys As Integer = 1000000, Optional keyOrdinality As ValueToKeyMappingEstimator.KeyOrdinality = Microsoft.ML.Transforms.ValueToKeyMappingEstimator+KeyOrdinality.ByOccurrence, Optional addKeyValueAnnotationsAsText As Boolean = false, Optional keyData As IDataView = Nothing) As ValueToKeyMappingEstimator

Parametri

catalog

TransformsCatalog.ConversionTransforms

Catalogo della trasformazione di conversione.

columns

InputOutputColumnPair[]

Colonne di input e output. I tipi di dati di input possono essere numerici, testo, booleano DateTime o DateTimeOffset.

maximumNumberOfKeys

Int32

Numero massimo di chiavi da mantenere per colonna durante il training.

keyOrdinality

ValueToKeyMappingEstimator.KeyOrdinality

Ordine in cui vengono assegnate le chiavi. Se impostato su ByOccurrence, le chiavi vengono assegnate nell'ordine rilevato. Se impostato su ByValue, i valori vengono ordinati e le chiavi vengono assegnate in base all'ordine di ordinamento.

addKeyValueAnnotationsAsText

Boolean

Se impostato su true, usare il tipo di testo per i valori, indipendentemente dal tipo di input effettivo. Quando si esegue il mapping inverso, i valori sono testo anziché il tipo di input originale.

keyData

IDataView

Usare un mapping predefinito tra valori e chiavi, anziché compilare il mapping dai dati di input durante il training. Se specificato, deve essere una singola colonna IDataView contenente i valori. Le chiavi vengono allocate in base al valore di keyOrdinality.

Restituisce

ValueToKeyMappingEstimator

Esempio

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

namespace Samples.Dynamic
{
    public static class MapValueToKeyMultiColumn
    {
        /// This example demonstrates the use of the ValueToKeyMappingEstimator, by
        /// mapping strings to KeyType values. For more on ML.NET KeyTypes see:
        /// https://github.com/dotnet/machinelearning/blob/main/docs/code/IDataViewTypeSystem.md#key-types
        /// It is possible to have multiple values map to the same category.
        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.
            var rawData = new[] {
                new DataPoint() { StudyTime = "0-4yrs" , Course = "CS" },
                new DataPoint() { StudyTime = "6-11yrs" , Course = "CS" },
                new DataPoint() { StudyTime = "12-25yrs" , Course = "LA" },
                new DataPoint() { StudyTime = "0-5yrs" , Course = "DS" }
            };

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

            // Constructs the ML.net pipeline
            var pipeline = mlContext.Transforms.Conversion.MapValueToKey(new[] {
                new  InputOutputColumnPair("StudyTimeCategory", "StudyTime"),
                new  InputOutputColumnPair("CourseCategory", "Course")
                },
                keyOrdinality: Microsoft.ML.Transforms.ValueToKeyMappingEstimator
                    .KeyOrdinality.ByValue, addKeyValueAnnotationsAsText: true);

            // Fits the pipeline to the data.
            IDataView transformedData = pipeline.Fit(data).Transform(data);

            // Getting the resulting data as an IEnumerable.
            // This will contain the newly created columns.
            IEnumerable<TransformedData> features = mlContext.Data.CreateEnumerable<
                TransformedData>(transformedData, reuseRowObject: false);

            Console.WriteLine($" StudyTime   StudyTimeCategory   Course    " +
                $"CourseCategory");

            foreach (var featureRow in features)
                Console.WriteLine($"{featureRow.StudyTime}\t\t" +
                    $"{featureRow.StudyTimeCategory}\t\t\t{featureRow.Course}\t\t" +
                    $"{featureRow.CourseCategory}");

            // TransformedData obtained post-transformation.
            //
            // StudyTime     StudyTimeCategory   Course    CourseCategory
            // 0-4yrs          1                   CS          1
            // 6-11yrs         4                   CS          1
            // 12-25yrs        3                   LA          3
            // 0-5yrs          2                   DS          2

            // If we wanted to provide the mapping, rather than letting the
            // transform create it, we could do so by creating an IDataView one
            // column containing the values to map to. If the values in the dataset
            // are not found in the lookup IDataView they will get mapped to the
            // missing value, 0. The keyData are shared among the columns, therefore
            // the keys are not contiguous for the column. Create the lookup map
            // data IEnumerable.
            var lookupData = new[] {
                new LookupMap { Key = "0-4yrs" },
                new LookupMap { Key = "6-11yrs" },
                new LookupMap { Key = "25+yrs"  },
                new LookupMap { Key = "CS" },
                new LookupMap { Key = "DS" },
                new LookupMap { Key = "LA"  }
            };

            // Convert to IDataView
            var lookupIdvMap = mlContext.Data.LoadFromEnumerable(lookupData);

            // Constructs the ML.net pipeline
            var pipelineWithLookupMap = mlContext.Transforms.Conversion
                .MapValueToKey(new[] {
                    new  InputOutputColumnPair("StudyTimeCategory", "StudyTime"),
                    new  InputOutputColumnPair("CourseCategory", "Course")
                    },
                    keyData: lookupIdvMap);

            // Fits the pipeline to the data.
            transformedData = pipelineWithLookupMap.Fit(data).Transform(data);

            // Getting the resulting data as an IEnumerable.
            // This will contain the newly created columns.
            features = mlContext.Data.CreateEnumerable<TransformedData>(
                transformedData, reuseRowObject: false);

            Console.WriteLine($" StudyTime   StudyTimeCategory  " +
                $"Course CourseCategory");

            foreach (var featureRow in features)
                Console.WriteLine($"{featureRow.StudyTime}\t\t" +
                    $"{featureRow.StudyTimeCategory}\t\t\t{featureRow.Course}\t\t" +
                    $"{featureRow.CourseCategory}");

            // StudyTime    StudyTimeCategory  Course     CourseCategory
            // 0 - 4yrs          1              CS              4
            // 6 - 11yrs         2              CS              4
            // 12 - 25yrs        0              LA              6
            // 0 - 5yrs          0              DS              5

        }

        private class DataPoint
        {
            public string StudyTime { get; set; }
            public string Course { get; set; }
        }

        private class TransformedData : DataPoint
        {
            public uint StudyTimeCategory { get; set; }
            public uint CourseCategory { get; set; }
        }

        // Type for the IDataView that will be serving as the map
        private class LookupMap
        {
            public string Key { get; set; }
        }
    }
}

Commenti

Questa trasformazione può funzionare su più coppie di colonne, creando un mapping per ogni coppia.

MapValueToKey(TransformsCatalog+ConversionTransforms, String, String, Int32, ValueToKeyMappingEstimator+KeyOrdinality, Boolean, IDataView)

Creare un ValueToKeyMappingEstimatoroggetto , che converte i valori categorici in chiavi numeriche.

public static Microsoft.ML.Transforms.ValueToKeyMappingEstimator MapValueToKey (this Microsoft.ML.TransformsCatalog.ConversionTransforms catalog, string outputColumnName, string inputColumnName = default, int maximumNumberOfKeys = 1000000, Microsoft.ML.Transforms.ValueToKeyMappingEstimator.KeyOrdinality keyOrdinality = Microsoft.ML.Transforms.ValueToKeyMappingEstimator+KeyOrdinality.ByOccurrence, bool addKeyValueAnnotationsAsText = false, Microsoft.ML.IDataView keyData = default);

static member MapValueToKey : Microsoft.ML.TransformsCatalog.ConversionTransforms * string * string * int * Microsoft.ML.Transforms.ValueToKeyMappingEstimator.KeyOrdinality * bool * Microsoft.ML.IDataView -> Microsoft.ML.Transforms.ValueToKeyMappingEstimator

<Extension()>
Public Function MapValueToKey (catalog As TransformsCatalog.ConversionTransforms, outputColumnName As String, Optional inputColumnName As String = Nothing, Optional maximumNumberOfKeys As Integer = 1000000, Optional keyOrdinality As ValueToKeyMappingEstimator.KeyOrdinality = Microsoft.ML.Transforms.ValueToKeyMappingEstimator+KeyOrdinality.ByOccurrence, Optional addKeyValueAnnotationsAsText As Boolean = false, Optional keyData As IDataView = Nothing) As ValueToKeyMappingEstimator

Parametri

catalog

TransformsCatalog.ConversionTransforms

Catalogo della trasformazione di conversione.

outputColumnName

String

Nome della colonna contenente le chiavi.

inputColumnName

String

Nome della colonna contenente i valori categorici. Se impostato su null, viene usato il valore dell'oggetto outputColumnName . I tipi di dati di input possono essere numerici, testo, booleano DateTime o DateTimeOffset.

maximumNumberOfKeys

Int32

Numero massimo di chiavi da mantenere per colonna durante il training.

keyOrdinality

ValueToKeyMappingEstimator.KeyOrdinality

Ordine in cui vengono assegnate le chiavi. Se impostato su ByOccurrence, le chiavi vengono assegnate nell'ordine rilevato. Se impostato su ByValue, i valori vengono ordinati e le chiavi vengono assegnate in base all'ordine di ordinamento.

addKeyValueAnnotationsAsText

Boolean

Se impostato su true, usare il tipo di testo per i valori, indipendentemente dal tipo di input effettivo. Quando si esegue il mapping inverso, i valori sono testo anziché il tipo di input originale.

keyData

IDataView

Usare un mapping predefinito tra valori e chiavi, anziché compilare il mapping dai dati di input durante il training. Se specificato, deve essere una singola colonna IDataView contenente i valori. Le chiavi vengono allocate in base al valore di keyOrdinality.

Restituisce

ValueToKeyMappingEstimator

Esempio

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

namespace Samples.Dynamic
{
    public class KeyToValueToKey
    {
        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.
            var rawData = new[] {
                new DataPoint() { Review = "animals birds cats dogs fish horse"},
                new DataPoint() { Review = "horse birds house fish duck cats"},
                new DataPoint() { Review = "car truck driver bus pickup"},
                new DataPoint() { Review = "car truck driver bus pickup horse"},
            };

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

            // A pipeline to convert the terms of the 'Review' column in 
            // making use of default settings.
            var defaultPipeline = mlContext.Transforms.Text.TokenizeIntoWords(
                "TokenizedText", nameof(DataPoint.Review)).Append(mlContext
                .Transforms.Conversion.MapValueToKey(nameof(TransformedData.Keys),
                "TokenizedText"));

            // Another pipeline, that customizes the advanced settings of the
            // ValueToKeyMappingEstimator. We can change the maximumNumberOfKeys to
            // limit how many keys will get generated out of the set of words, and
            // condition the order in which they get evaluated by changing
            // keyOrdinality from the default ByOccurence (order in which they get
            // encountered) to value/alphabetically.
            var customizedPipeline = mlContext.Transforms.Text.TokenizeIntoWords(
                "TokenizedText", nameof(DataPoint.Review)).Append(mlContext
                .Transforms.Conversion.MapValueToKey(nameof(TransformedData.Keys),
                "TokenizedText", maximumNumberOfKeys: 10, keyOrdinality:
                ValueToKeyMappingEstimator.KeyOrdinality.ByValue));

            // The transformed data.
            var transformedDataDefault = defaultPipeline.Fit(trainData).Transform(
                trainData);

            var transformedDataCustomized = customizedPipeline.Fit(trainData)
                .Transform(trainData);

            // Getting the resulting data as an IEnumerable.
            // This will contain the newly created columns.
            IEnumerable<TransformedData> defaultData = mlContext.Data.
                CreateEnumerable<TransformedData>(transformedDataDefault,
                reuseRowObject: false);

            IEnumerable<TransformedData> customizedData = mlContext.Data.
                CreateEnumerable<TransformedData>(transformedDataCustomized,
                reuseRowObject: false);

            Console.WriteLine($"Keys");
            foreach (var dataRow in defaultData)
                Console.WriteLine($"{string.Join(',', dataRow.Keys)}");
            // Expected output:
            //  Keys
            //  1,2,3,4,5,6
            //  6,2,7,5,8,3
            //  9,10,11,12,13
            //  9,10,11,12,13,6

            Console.WriteLine($"Keys");
            foreach (var dataRow in customizedData)
                Console.WriteLine($"{string.Join(',', dataRow.Keys)}");
            // Expected output:
            //  Keys
            //  1,2,4,5,7,8
            //  8,2,9,7,6,4
            //  3,10,0,0,0
            //  3,10,0,0,0,8
            // Retrieve the original values, by appending the KeyToValue estimator to
            // the existing pipelines to convert the keys back to the strings.
            var pipeline = defaultPipeline.Append(mlContext.Transforms.Conversion
                .MapKeyToValue(nameof(TransformedData.Keys)));

            transformedDataDefault = pipeline.Fit(trainData).Transform(trainData);

            // Preview of the DefaultColumnName column obtained.
            var originalColumnBack = transformedDataDefault.GetColumn<VBuffer<
                ReadOnlyMemory<char>>>(transformedDataDefault.Schema[nameof(
                TransformedData.Keys)]);

            foreach (var row in originalColumnBack)
            {
                foreach (var value in row.GetValues())
                    Console.Write($"{value} ");
                Console.WriteLine("");
            }

            // Expected output:
            //  animals birds cats dogs fish horse
            //  horse birds house fish duck cats
            //  car truck driver bus pickup
            //  car truck driver bus pickup horse
        }

        private class DataPoint
        {
            public string Review { get; set; }
        }

        private class TransformedData : DataPoint
        {
            public uint[] Keys { get; set; }
        }
    }
}