DataOperationsCatalog.LoadFromEnumerable Metodo

Origine:

DataOperationsCatalog.cs

Origine:

DataOperationsCatalog.cs

Origine:

DataOperationsCatalog.cs

public Microsoft.ML.IDataView LoadFromEnumerable<TRow>(System.Collections.Generic.IEnumerable<TRow> data, Microsoft.ML.Data.SchemaDefinition schemaDefinition = default) where TRow : class;

member this.LoadFromEnumerable : seq<'Row (requires 'Row : null)> * Microsoft.ML.Data.SchemaDefinition -> Microsoft.ML.IDataView (requires 'Row : null)

Public Function LoadFromEnumerable(Of TRow As Class) (data As IEnumerable(Of TRow), Optional schemaDefinition As SchemaDefinition = Nothing) As IDataView

Parametri di tipo

Parametri

Valori restituiti

Oggetto costruito IDataView.

Esempio

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

namespace Samples.Dynamic
{
    public static class LoadFromEnumerable
    {
        // Creating IDataView from IEnumerable, and setting the size of the vector
        // at runtime. When the data model is defined through types, setting the
        // size of the vector is done through the VectorType annotation. When the
        // size of the data is not known at compile time, the Schema can be directly
        // modified at runtime and the size of the vector set there. This is
        // important, because most of the ML.NET trainers require the Features
        // vector to be of known size. 
        public static void Example()
        {
            // Create a new context for ML.NET operations. It can be used for
            // exception tracking and logging, as a catalog of available operations
            // and as the source of randomness.
            var mlContext = new MLContext();

            // Get a small dataset as an IEnumerable.
            IEnumerable<DataPointVector> enumerableKnownSize = new DataPointVector[]
            {
               new DataPointVector{ Features = new float[]{ 1.2f, 3.4f, 4.5f, 3.2f,
                   7,5f } },

               new DataPointVector{ Features = new float[]{ 4.2f, 3.4f, 14.65f,
                   3.2f, 3,5f } },

               new DataPointVector{ Features = new float[]{ 1.6f, 3.5f, 4.5f, 6.2f,
                   3,5f } },

            };

            // Load dataset into an IDataView. 
            IDataView data = mlContext.Data.LoadFromEnumerable(enumerableKnownSize);
            var featureColumn = data.Schema["Features"].Type as VectorDataViewType;
            // Inspecting the schema
            Console.WriteLine($"Is the size of the Features column known: " +
                $"{featureColumn.IsKnownSize}.\nSize: {featureColumn.Size}");

            // Preview
            //
            // Is the size of the Features column known? True.
            // Size: 5.

            // If the size of the vector is unknown at compile time, it can be set 
            // at runtime.
            IEnumerable<DataPoint> enumerableUnknownSize = new DataPoint[]
            {
               new DataPoint{ Features = new float[]{ 1.2f, 3.4f, 4.5f } },
               new DataPoint{ Features = new float[]{ 4.2f, 3.4f, 1.6f } },
               new DataPoint{ Features = new float[]{ 1.6f, 3.5f, 4.5f } },
            };

            // The feature dimension (typically this will be the Count of the array 
            // of the features vector known at runtime).
            int featureDimension = 3;
            var definedSchema = SchemaDefinition.Create(typeof(DataPoint));
            featureColumn = definedSchema["Features"]
                .ColumnType as VectorDataViewType;

            Console.WriteLine($"Is the size of the Features column known: " +
                $"{featureColumn.IsKnownSize}.\nSize: {featureColumn.Size}");

            // Preview
            //
            // Is the size of the Features column known? False.
            // Size: 0.

            // Set the column type to be a known-size vector.
            var vectorItemType = ((VectorDataViewType)definedSchema[0].ColumnType)
                .ItemType;
            definedSchema[0].ColumnType = new VectorDataViewType(vectorItemType,
                featureDimension);

            // Read the data into an IDataView with the modified schema supplied in
            IDataView data2 = mlContext.Data
                .LoadFromEnumerable(enumerableUnknownSize, definedSchema);

            featureColumn = data2.Schema["Features"].Type as VectorDataViewType;
            // Inspecting the schema
            Console.WriteLine($"Is the size of the Features column known: " +
                $"{featureColumn.IsKnownSize}.\nSize: {featureColumn.Size}");

            // Preview
            //
            // Is the size of the Features column known? True. 
            // Size: 3.
        }
    }

    public class DataPoint
    {
        public float[] Features { get; set; }
    }

    public class DataPointVector
    {
        [VectorType(5)]
        public float[] Features { get; set; }
    }
}

Origine:

DataOperationsCatalog.cs

Origine:

DataOperationsCatalog.cs

Origine:

DataOperationsCatalog.cs

public Microsoft.ML.IDataView LoadFromEnumerable<TRow>(System.Collections.Generic.IEnumerable<TRow> data, Microsoft.ML.DataViewSchema schema) where TRow : class;

member this.LoadFromEnumerable : seq<'Row (requires 'Row : null)> * Microsoft.ML.DataViewSchema -> Microsoft.ML.IDataView (requires 'Row : null)

Public Function LoadFromEnumerable(Of TRow As Class) (data As IEnumerable(Of TRow), schema As DataViewSchema) As IDataView

Parametri di tipo

Parametri

Valori restituiti

Oggetto IDataView con l'oggetto specificato schema.

Commenti

L'utente mantiene la data proprietà di e la visualizzazione dati risultante non modificherà mai il contenuto di data. Poiché IDataView si presuppone che non sia modificabile, l'utente dovrebbe supportare più enumerazioni di data che restituirebbero gli stessi risultati, a meno che l'utente non sappia che i dati verranno cursorati una sola volta. Un utilizzo tipico per la visualizzazione dei dati in streaming può essere: creare la vista dati che carica i dati in modo differimento in base alle esigenze, quindi applicare trasformazioni con training preliminare e cursore attraverso di essa per i risultati della trasformazione. Un uso pratico di questo sarebbe fornire i nomi delle colonne di funzionalità tramite .DataViewSchema.Annotations