Beispiel #1
0
 public INgramExtractorFactory CreateComponent(IHostEnvironment env, TermLoaderArguments loaderArgs)
 {
     return(Create(env, this, loaderArgs));
 }
Beispiel #2
0
        public static IDataTransform Create(IHostEnvironment env, Arguments args, IDataView input,
                                            TermLoaderArguments termLoaderArgs = null)
        {
            Contracts.CheckValue(env, nameof(env));
            var h = env.Register(LoaderSignature);

            h.CheckValue(args, nameof(args));
            h.CheckValue(input, nameof(input));
            h.CheckUserArg(Utils.Size(args.Column) > 0, nameof(args.Column), "Columns must be specified");

            IDataView view      = input;
            var       termCols  = new List <Column>();
            var       isTermCol = new bool[args.Column.Length];

            for (int i = 0; i < args.Column.Length; i++)
            {
                var col = args.Column[i];

                h.CheckNonWhiteSpace(col.Name, nameof(col.Name));
                h.CheckNonWhiteSpace(col.Source, nameof(col.Source));
                int colId;
                if (input.Schema.TryGetColumnIndex(col.Source, out colId) &&
                    input.Schema.GetColumnType(colId).ItemType.IsText)
                {
                    termCols.Add(col);
                    isTermCol[i] = true;
                }
            }

            // If the column types of args.column are text, apply term transform to convert them to keys.
            // Otherwise, skip term transform and apply ngram transform directly.
            // This logic allows NgramExtractorTransform to handle both text and key input columns.
            // Note: ngram transform handles the validation of the types natively (in case the types
            // of args.column are not text nor keys).
            if (termCols.Count > 0)
            {
                TermTransform.Arguments   termArgs   = null;
                NADropTransform.Arguments naDropArgs = null;
                if (termLoaderArgs != null)
                {
                    termArgs =
                        new TermTransform.Arguments()
                    {
                        MaxNumTerms = int.MaxValue,
                        Terms       = termLoaderArgs.Terms,
                        Term        = termLoaderArgs.Term,
                        DataFile    = termLoaderArgs.DataFile,
                        Loader      = termLoaderArgs.Loader,
                        TermsColumn = termLoaderArgs.TermsColumn,
                        Sort        = termLoaderArgs.Sort,
                        Column      = new TermTransform.Column[termCols.Count]
                    };

                    if (termLoaderArgs.DropUnknowns)
                    {
                        naDropArgs = new NADropTransform.Arguments {
                            Column = new NADropTransform.Column[termCols.Count]
                        }
                    }
                    ;
                }
                else
                {
                    termArgs =
                        new TermTransform.Arguments()
                    {
                        MaxNumTerms = Utils.Size(args.MaxNumTerms) > 0 ? args.MaxNumTerms[0] : NgramTransform.Arguments.DefaultMaxTerms,
                        Column      = new TermTransform.Column[termCols.Count]
                    };
                }

                for (int iinfo = 0; iinfo < termCols.Count; iinfo++)
                {
                    var column = termCols[iinfo];
                    termArgs.Column[iinfo] =
                        new TermTransform.Column()
                    {
                        Name        = column.Name,
                        Source      = column.Source,
                        MaxNumTerms = Utils.Size(column.MaxNumTerms) > 0 ? column.MaxNumTerms[0] : default(int?)
                    };

                    if (naDropArgs != null)
                    {
                        naDropArgs.Column[iinfo] = new NADropTransform.Column {
                            Name = column.Name, Source = column.Name
                        }
                    }
                    ;
                }

                view = new TermTransform(h, termArgs, view);
                if (naDropArgs != null)
                {
                    view = new NADropTransform(h, naDropArgs, view);
                }
            }

            var ngramArgs =
                new NgramTransform.Arguments()
            {
                MaxNumTerms = args.MaxNumTerms,
                NgramLength = args.NgramLength,
                SkipLength  = args.SkipLength,
                AllLengths  = args.AllLengths,
                Weighting   = args.Weighting,
                Column      = new NgramTransform.Column[args.Column.Length]
            };

            for (int iinfo = 0; iinfo < args.Column.Length; iinfo++)
            {
                var column = args.Column[iinfo];
                ngramArgs.Column[iinfo] =
                    new NgramTransform.Column()
                {
                    Name        = column.Name,
                    Source      = isTermCol[iinfo] ? column.Name : column.Source,
                    AllLengths  = column.AllLengths,
                    MaxNumTerms = column.MaxNumTerms,
                    NgramLength = column.NgramLength,
                    SkipLength  = column.SkipLength,
                    Weighting   = column.Weighting
                };
            }

            return(new NgramTransform(h, ngramArgs, view));
        }
Beispiel #3
0
        public static IDataTransform Create(IHostEnvironment env, Arguments args, IDataView input,
                                            TermLoaderArguments termLoaderArgs = null)
        {
            Contracts.CheckValue(env, nameof(env));
            var h = env.Register(LoaderSignature);

            h.CheckValue(args, nameof(args));
            h.CheckValue(input, nameof(input));
            h.CheckUserArg(Utils.Size(args.Column) > 0, nameof(args.Column), "Columns must be specified");

            // To each input column to the NgramHashExtractorArguments, a HashTransform using 31
            // bits (to minimize collisions) is applied first, followed by an NgramHashTransform.
            IDataView view = input;

            List <TermTransform.Column> termCols = null;

            if (termLoaderArgs != null)
            {
                termCols = new List <TermTransform.Column>();
            }
            var hashColumns      = new List <HashTransform.Column>();
            var ngramHashColumns = new NgramHashTransform.Column[args.Column.Length];

            var colCount = args.Column.Length;

            // The NGramHashExtractor has a ManyToOne column type. To avoid stepping over the source
            // column name when a 'name' destination column name was specified, we use temporary column names.
            string[][] tmpColNames = new string[colCount][];
            for (int iinfo = 0; iinfo < colCount; iinfo++)
            {
                var column = args.Column[iinfo];
                h.CheckUserArg(!string.IsNullOrWhiteSpace(column.Name), nameof(column.Name));
                h.CheckUserArg(Utils.Size(column.Source) > 0 &&
                               column.Source.All(src => !string.IsNullOrWhiteSpace(src)), nameof(column.Source));

                int srcCount = column.Source.Length;
                tmpColNames[iinfo] = new string[srcCount];
                for (int isrc = 0; isrc < srcCount; isrc++)
                {
                    var tmpName = input.Schema.GetTempColumnName(column.Source[isrc]);
                    tmpColNames[iinfo][isrc] = tmpName;
                    if (termLoaderArgs != null)
                    {
                        termCols.Add(
                            new TermTransform.Column
                        {
                            Name   = tmpName,
                            Source = column.Source[isrc]
                        });
                    }

                    hashColumns.Add(
                        new HashTransform.Column
                    {
                        Name       = tmpName,
                        Source     = termLoaderArgs == null ? column.Source[isrc] : tmpName,
                        HashBits   = 30,
                        Seed       = column.Seed,
                        Ordered    = false,
                        InvertHash = column.InvertHash
                    });
                }

                ngramHashColumns[iinfo] =
                    new NgramHashTransform.Column
                {
                    Name           = column.Name,
                    Source         = tmpColNames[iinfo],
                    AllLengths     = column.AllLengths,
                    HashBits       = column.HashBits,
                    NgramLength    = column.NgramLength,
                    RehashUnigrams = false,
                    Seed           = column.Seed,
                    SkipLength     = column.SkipLength,
                    Ordered        = column.Ordered,
                    InvertHash     = column.InvertHash,
                    // REVIEW: This is an ugly internal hack to get around
                    // the problem that we want the *original* source names surfacing
                    // in the descriptions where appropriate, rather than _tmp000 and
                    // what have you. The alternative is we do something elaborate
                    // with metadata or something but I'm not sure that's better.
                    FriendlyNames = column.FriendlyNames
                };
            }

            if (termLoaderArgs != null)
            {
                h.Assert(Utils.Size(termCols) == hashColumns.Count);
                var termArgs =
                    new TermTransform.Arguments()
                {
                    MaxNumTerms = int.MaxValue,
                    Terms       = termLoaderArgs.Terms,
                    Term        = termLoaderArgs.Term,
                    DataFile    = termLoaderArgs.DataFile,
                    Loader      = termLoaderArgs.Loader,
                    TermsColumn = termLoaderArgs.TermsColumn,
                    Sort        = termLoaderArgs.Sort,
                    Column      = termCols.ToArray()
                };
                view = TermTransform.Create(h, termArgs, view);

                if (termLoaderArgs.DropUnknowns)
                {
                    var naDropArgs = new NADropTransform.Arguments {
                        Column = new NADropTransform.Column[termCols.Count]
                    };
                    for (int iinfo = 0; iinfo < termCols.Count; iinfo++)
                    {
                        naDropArgs.Column[iinfo] =
                            new NADropTransform.Column {
                            Name = termCols[iinfo].Name, Source = termCols[iinfo].Name
                        };
                    }
                    view = new NADropTransform(h, naDropArgs, view);
                }
            }

            // Args for the Hash function with multiple columns
            var hashArgs =
                new HashTransform.Arguments
            {
                HashBits   = 31,
                Seed       = args.Seed,
                Ordered    = false,
                Column     = hashColumns.ToArray(),
                InvertHash = args.InvertHash
            };

            view = new HashTransform(h, hashArgs, view);

            // creating the NgramHash function
            var ngramHashArgs =
                new NgramHashTransform.Arguments
            {
                AllLengths     = args.AllLengths,
                HashBits       = args.HashBits,
                NgramLength    = args.NgramLength,
                SkipLength     = args.SkipLength,
                RehashUnigrams = false,
                Ordered        = args.Ordered,
                Seed           = args.Seed,
                Column         = ngramHashColumns,
                InvertHash     = args.InvertHash
            };

            view = new NgramHashTransform(h, ngramHashArgs, view);
            return(new DropColumnsTransform(h, new DropColumnsTransform.Arguments()
            {
                Column = tmpColNames.SelectMany(cols => cols).ToArray()
            }, view));
        }