TextCatalog.RemoveStopWords Metode

Definisi

Ruang nama:

Microsoft.ML

Rakitan:

Microsoft.ML.Transforms.dll

Paket:

Microsoft.ML v3.0.1

Buat CustomStopWordsRemovingEstimator, yang menyalin data dari kolom yang ditentukan ke inputColumnName kolom baru: outputColumnName dan menghapus teks yang ditentukan dari stopwords kolom tersebut.

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

Katalog transformasi.

outputColumnName

String

Nama kolom yang dihasilkan dari transformasi inputColumnName. Jenis data kolom ini akan menjadi vektor teks ukuran variabel.

inputColumnName

String

Nama kolom untuk menyalin data. Estimator ini beroperasi melalui vektor teks.

stopwords

String[]

Array kata yang akan dihapus.

Mengembalikan

CustomStopWordsRemovingEstimator

Contoh

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; }
        }
    }
}