TextCatalog.RemoveStopWords Methode

Definition

Namespace:

Microsoft.ML

Assembly:

Microsoft.ML.Transforms.dll

Paket:

Microsoft.ML v2.0.0

Erstellen Sie einen CustomStopWordsRemovingEstimator, der die Daten aus der spalte kopiert, die in inputColumnName einer neuen Spalte angegeben ist: outputColumnName und entfernt text, der darin stopwords angegeben ist.

public static Microsoft.ML.Transforms.Text.CustomStopWordsRemovingEstimator RemoveStopWords (this Microsoft.ML.TransformsCatalog.TextTransforms catalog, string outputColumnName, string inputColumnName = default, params string[] stopwords);

static member RemoveStopWords : Microsoft.ML.TransformsCatalog.TextTransforms * string * string * string[] -> Microsoft.ML.Transforms.Text.CustomStopWordsRemovingEstimator

<Extension()>
Public Function RemoveStopWords (catalog As TransformsCatalog.TextTransforms, outputColumnName As String, Optional inputColumnName As String = Nothing, ParamArray stopwords As String()) As CustomStopWordsRemovingEstimator

Parameter

catalog

TransformsCatalog.TextTransforms

Der Katalog der Transformation.

outputColumnName

String

Name der Spalte, die aus der Transformation von inputColumnName. Der Datentyp dieser Spalte ist ein Vektor mit variabler Größe des Texts.

inputColumnName

String

Name der Spalte, aus der die Daten kopiert werden sollen. Dieser Schätzer wird über einen Textvektor betrieben.

stopwords

String[]

Array von Wörtern, die entfernt werden sollen.

Gibt zurück

CustomStopWordsRemovingEstimator

Beispiele

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

namespace Samples.Dynamic
{
    public static class RemoveStopWords
    {
        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 an empty list as the dataset. The 'RemoveStopWords' does not
            // require training data as the estimator
            // ('CustomStopWordsRemovingEstimator') created by 'RemoveStopWords' API
            // is not a trainable estimator. The empty list is only needed to pass
            // input schema to the pipeline.
            var emptySamples = new List<TextData>();

            // Convert sample list to an empty IDataView.
            var emptyDataView = mlContext.Data.LoadFromEnumerable(emptySamples);

            // A pipeline for removing stop words from input text/string.
            // The pipeline first tokenizes text into words then removes stop words.
            // The 'RemoveStopWords' API ignores casing of the text/string e.g. 
            // 'tHe' and 'the' are considered the same stop words.
            var textPipeline = mlContext.Transforms.Text.TokenizeIntoWords("Words",
                "Text")
                .Append(mlContext.Transforms.Text.RemoveStopWords(
                "WordsWithoutStopWords", "Words", stopwords:
                new[] { "a", "the", "from", "by" }));

            // Fit to data.
            var textTransformer = textPipeline.Fit(emptyDataView);

            // Create the prediction engine to remove the stop words from the input
            // text /string.
            var predictionEngine = mlContext.Model.CreatePredictionEngine<TextData,
                TransformedTextData>(textTransformer);

            // Call the prediction API to remove stop words.
            var data = new TextData()
            {
                Text = "ML.NET's RemoveStopWords API " +
                "removes stop words from tHe text/string using a list of stop " +
                "words provided by the user."
            };

            var prediction = predictionEngine.Predict(data);

            // Print the length of the word vector after the stop words removed.
            Console.WriteLine("Number of words: " + prediction.WordsWithoutStopWords
                .Length);

            // Print the word vector without stop words.
            Console.WriteLine("\nWords without stop words: " + string.Join(",",
                prediction.WordsWithoutStopWords));

            //  Expected output:
            //   Number of words: 14
            //   Words without stop words: ML.NET's,RemoveStopWords,API,removes,stop,words,text/string,using,list,of,stop,words,provided,user.
        }

        private class TextData
        {
            public string Text { get; set; }
        }

        private class TransformedTextData : TextData
        {
            public string[] WordsWithoutStopWords { get; set; }
        }
    }
}