TransformExtensionsCatalog.Concatenate Metodo

Definizione

Spazio dei nomi:

Microsoft.ML

Assembly:

Microsoft.ML.Data.dll

Pacchetto:

Microsoft.ML v2.0.0

Creare un ColumnConcatenatingEstimatoroggetto , che concatena una o più colonne di input in una nuova colonna di output.

public static Microsoft.ML.Transforms.ColumnConcatenatingEstimator Concatenate (this Microsoft.ML.TransformsCatalog catalog, string outputColumnName, params string[] inputColumnNames);

static member Concatenate : Microsoft.ML.TransformsCatalog * string * string[] -> Microsoft.ML.Transforms.ColumnConcatenatingEstimator

<Extension()>
Public Function Concatenate (catalog As TransformsCatalog, outputColumnName As String, ParamArray inputColumnNames As String()) As ColumnConcatenatingEstimator

Parametri

catalog

TransformsCatalog

Catalogo della trasformazione.

outputColumnName

String

Nome della colonna risultante dalla trasformazione di inputColumnNames. Il tipo di dati di questa colonna sarà un vettore del tipo di dati delle colonne di input.

inputColumnNames

String[]

Nome delle colonne da concatenare. Questo strumento di stima opera su qualsiasi tipo di dati ad eccezione del tipo di chiave. Se vengono fornite più colonne, devono avere tutti lo stesso tipo di dati.

Restituisce

ColumnConcatenatingEstimator

Esempio

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

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

            // Create a small dataset as an IEnumerable.
            var samples = new List<InputData>()
            {
                new InputData(){ Feature1 = 0.1f, Feature2 = new[]{ 1.1f, 2.1f,
                    3.1f }, Feature3 = 1 },

                new InputData(){ Feature1 = 0.2f, Feature2 = new[]{ 1.2f, 2.2f,
                    3.2f }, Feature3 = 2 },

                new InputData(){ Feature1 = 0.3f, Feature2 = new[]{ 1.3f, 2.3f,
                    3.3f }, Feature3 = 3 },

                new InputData(){ Feature1 = 0.4f, Feature2 = new[]{ 1.4f, 2.4f,
                    3.4f }, Feature3 = 4 },

                new InputData(){ Feature1 = 0.5f, Feature2 = new[]{ 1.5f, 2.5f,
                    3.5f }, Feature3 = 5 },

                new InputData(){ Feature1 = 0.6f, Feature2 = new[]{ 1.6f, 2.6f,
                    3.6f }, Feature3 = 6 },
            };

            // Convert training data to IDataView.
            var dataview = mlContext.Data.LoadFromEnumerable(samples);

            // A pipeline for concatenating the "Feature1", "Feature2" and
            // "Feature3" columns together into a vector that will be the Features
            // column. Concatenation is necessary because trainers take feature
            // vectors as inputs.
            //
            // Please note that the "Feature3" column is converted from int32 to
            // float using the ConvertType. The Concatenate requires all columns to
            // be of same type.
            var pipeline = mlContext.Transforms.Conversion.ConvertType("Feature3",
                outputKind: DataKind.Single)
                .Append(mlContext.Transforms.Concatenate("Features", new[]
                    { "Feature1", "Feature2", "Feature3" }));

            // The transformed data.
            var transformedData = pipeline.Fit(dataview).Transform(dataview);

            // Now let's take a look at what this concatenation did.
            // We can extract the newly created column as an IEnumerable of
            // TransformedData.
            var featuresColumn = mlContext.Data.CreateEnumerable<TransformedData>(
                transformedData, reuseRowObject: false);

            // And we can write out a few rows
            Console.WriteLine($"Features column obtained post-transformation.");
            foreach (var featureRow in featuresColumn)
                Console.WriteLine(string.Join(" ", featureRow.Features));

            // Expected output:
            //  Features column obtained post-transformation.
            //  0.1 1.1 2.1 3.1 1
            //  0.2 1.2 2.2 3.2 2
            //  0.3 1.3 2.3 3.3 3
            //  0.4 1.4 2.4 3.4 4
            //  0.5 1.5 2.5 3.5 5
            //  0.6 1.6 2.6 3.6 6
        }

        private class InputData
        {
            public float Feature1;
            [VectorType(3)]
            public float[] Feature2;
            public int Feature3;
        }

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