/// <summary>
/// Load a <see cref="IDataView"/> from a text file using <see cref="TextLoader"/>.
/// Note that <see cref="IDataView"/>'s are lazy, so no actual loading happens here, just schema validation.
/// </summary>
/// <param name="catalog">The <see cref="DataOperationsCatalog"/> catalog.</param>
/// <param name="path">Specifies a file or path of files from which to load.</param>
/// <param name="options">Defines the settings of the load operation. No need to specify a Columns field,
/// as columns will be infered by this method.</param>
/// <returns>The data view.</returns>
public static IDataView LoadFromTextFile <TInput>(this DataOperationsCatalog catalog, string path,
TextLoader.Options options)
{
CheckValidPathContents(path);
return(TextLoader.CreateTextLoader <TInput>(CatalogUtils.GetEnvironment(catalog), options)
.Load(new MultiFileSource(path)));
}
/// <summary>
/// Create a text loader <see cref="TextLoader"/> by inferencing the dataset schema from a data model type.
/// </summary>
/// <typeparam name="TInput">Defines the schema of the data to be loaded. Use public fields or properties
/// decorated with <see cref="LoadColumnAttribute"/> (and possibly other attributes) to specify the column
/// names and their data types in the schema of the loaded data.</typeparam>
/// <param name="catalog">The <see cref="DataOperationsCatalog"/> catalog.</param>
/// <param name="separatorChar">Column separator character. Default is '\t'</param>
/// <param name="hasHeader">Whether the file has a header with feature names. When a <see paramref="dataSample"/> is provided, <see langword="true"/>
/// indicates that the first line in the <see paramref="dataSample"/> will be used for feature names, and that when <see cref="TextLoader.Load(IMultiStreamSource)"/>
/// is called, the first line will be skipped. When there is no <see paramref="dataSample"/> provided, <see langword="true"/> just indicates that the loader should
/// skip the first line when <see cref="TextLoader.Load(IMultiStreamSource)"/> is called, but columns will not have slot names annotations. This is
/// because the output schema is made when the loader is created, and not when <see cref="TextLoader.Load(IMultiStreamSource)"/> is called.</param>
/// <param name="dataSample">The optional location of a data sample. The sample can be used to infer slot name annotations if present.</param>
/// <param name="allowQuoting">Whether the input may include double-quoted values. This parameter is used to distinguish separator characters
/// in an input value from actual separators. When <see langword="true"/>, separators within double quotes are treated as part of the
/// input value. When <see langword="false"/>, all separators, even those whitin quotes, are treated as delimiting a new column.</param>
/// <param name="trimWhitespace">Remove trailing whitespace from lines.</param>
/// <param name="allowSparse">Whether the input may include sparse representations. For example, a row containing
/// "5 2:6 4:3" means that there are 5 columns, and the only non-zero are columns 2 and 4, which have values 6 and 3,
/// respectively. Column indices are zero-based, so columns 2 and 4 represent the 3rd and 5th columns.
/// A column may also have dense values followed by sparse values represented in this fashion. For example,
/// a row containing "1 2 5 2:6 4:3" represents two dense columns with values 1 and 2, followed by 5 sparsely represented
/// columns with values 0, 0, 6, 0, and 3. The indices of the sparse columns start from 0, even though 0 represents the third column.</param>
public static TextLoader CreateTextLoader <TInput>(this DataOperationsCatalog catalog,
char separatorChar = TextLoader.Defaults.Separator,
bool hasHeader = TextLoader.Defaults.HasHeader,
IMultiStreamSource dataSample = null,
bool allowQuoting = TextLoader.Defaults.AllowQuoting,
bool trimWhitespace = TextLoader.Defaults.TrimWhitespace,
bool allowSparse = TextLoader.Defaults.AllowSparse)
=> TextLoader.CreateTextLoader <TInput>(CatalogUtils.GetEnvironment(catalog), hasHeader, separatorChar, allowQuoting,
allowSparse, trimWhitespace, dataSample: dataSample);
/// <summary>
/// Load a <see cref="IDataView"/> from a text file using <see cref="TextLoader"/>.
/// Note that <see cref="IDataView"/>'s are lazy, so no actual loading happens here, just schema validation.
/// </summary>
/// <param name="catalog">The <see cref="DataOperationsCatalog"/> catalog.</param>
/// <param name="path">Specifies a file from which to load.</param>
/// <param name="options">Defines the settings of the load operation. No need to specify a Columns field,
/// as columns will be infered by this method.</param>
/// <returns>The data view.</returns>
public static IDataView LoadFromTextFile <TInput>(this DataOperationsCatalog catalog, string path,
TextLoader.Options options)
{
Contracts.CheckNonEmpty(path, nameof(path));
if (!File.Exists(path))
{
throw Contracts.ExceptParam(nameof(path), "File does not exist at path: {0}", path);
}
return(TextLoader.CreateTextLoader <TInput>(CatalogUtils.GetEnvironment(catalog), options)
.Load(new MultiFileSource(path)));
}
/// <summary>
/// Load a <see cref="IDataView"/> from a text file using <see cref="TextLoader"/>.
/// Note that <see cref="IDataView"/>'s are lazy, so no actual loading happens here, just schema validation.
/// </summary>
/// <param name="catalog">The <see cref="DataOperationsCatalog"/> catalog.</param>
/// <param name="path">The path to the file(s).</param>
/// <param name="separatorChar">Column separator character. Default is '\t'</param>
/// <param name="hasHeader">Whether the file has a header. When <see langword="true"/>, the loader will skip the first line when
/// <see cref="TextLoader.Load(IMultiStreamSource)"/> is called.</param>
/// <param name="allowQuoting">Whether the input may include double-quoted values. This parameter is used to distinguish separator characters
/// in an input value from actual separators. When <see langword="true"/>, separators within double quotes are treated as part of the
/// input value. When <see langword="false"/>, all separators, even those whitin quotes, are treated as delimiting a new column.
/// It is also used to distinguish empty values from missing values. When <see langword="true"/>, missing value are denoted by consecutive
/// separators and empty values by \"\". When <see langword="false"/>, empty values are denoted by consecutive separators and missing
/// values by the default missing value for each type documented in <see cref="DataKind"/>.</param>
/// <param name="trimWhitespace">Remove trailing whitespace from lines.</param>
/// <param name="allowSparse">Whether the input may include sparse representations. For example, a row containing
/// "5 2:6 4:3" means that there are 5 columns, and the only non-zero are columns 2 and 4, which have values 6 and 3,
/// respectively. Column indices are zero-based, so columns 2 and 4 represent the 3rd and 5th columns.
/// A column may also have dense values followed by sparse values represented in this fashion. For example,
/// a row containing "1 2 5 2:6 4:3" represents two dense columns with values 1 and 2, followed by 5 sparsely represented
/// columns with values 0, 0, 6, 0, and 3. The indices of the sparse columns start from 0, even though 0 represents the third column.</param>
/// <returns>The data view.</returns>
public static IDataView LoadFromTextFile <TInput>(this DataOperationsCatalog catalog,
string path,
char separatorChar = TextLoader.Defaults.Separator,
bool hasHeader = TextLoader.Defaults.HasHeader,
bool allowQuoting = TextLoader.Defaults.AllowQuoting,
bool trimWhitespace = TextLoader.Defaults.TrimWhitespace,
bool allowSparse = TextLoader.Defaults.AllowSparse)
{
CheckValidPathContents(path);
// REVIEW: it is almost always a mistake to have a 'trainable' text loader here.
// Therefore, we are going to disallow data sample.
return(TextLoader.CreateTextLoader <TInput>(CatalogUtils.GetEnvironment(catalog), hasHeader, separatorChar,
allowQuoting, allowSparse, trimWhitespace).Load(new MultiFileSource(path)));
}
/// <summary>
/// Load a <see cref="IDataView"/> from a text file using <see cref="TextLoader"/>.
/// Note that <see cref="IDataView"/>'s are lazy, so no actual loading happens here, just schema validation.
/// </summary>
/// <param name="catalog">The <see cref="DataOperationsCatalog"/> catalog.</param>
/// <param name="path">The path to the file.</param>
/// <param name="separatorChar">Column separator character. Default is '\t'</param>
/// <param name="hasHeader">Whether the file has a header with feature names. Note: If a TextLoader is created with hasHeader = true but without a
/// dataSample, then vector columns made by TextLoader will not contain slot name annotations (slots being the elements of the given vector column),
/// because the output schema is made when the TextLoader is made, and not when <see cref="TextLoader.Load(IMultiStreamSource)"/> is called.
/// In addition, the case where dataSample = null and hasHeader = true indicates to the loader that when it is given a file when Load()
/// is called, it needs to skip the first line.</param>
/// <param name="allowQuoting">Whether the input may include quoted values,
/// which can contain separator characters, colons,
/// and distinguish empty values from missing values. When true, consecutive separators
/// denote a missing value and an empty value is denoted by \"\".
/// When false, consecutive separators denote an empty value.</param>
/// <param name="trimWhitespace">Remove trailing whitespace from lines</param>
/// <param name="allowSparse">Whether the input may include sparse representations for example,
/// if one of the row contains "5 2:6 4:3" that's mean there are 5 columns all zero
/// except for 3rd and 5th columns which have values 6 and 3</param>
/// <returns>The data view.</returns>
public static IDataView LoadFromTextFile <TInput>(this DataOperationsCatalog catalog,
string path,
char separatorChar = TextLoader.Defaults.Separator,
bool hasHeader = TextLoader.Defaults.HasHeader,
bool allowQuoting = TextLoader.Defaults.AllowQuoting,
bool trimWhitespace = TextLoader.Defaults.TrimWhitespace,
bool allowSparse = TextLoader.Defaults.AllowSparse)
{
Contracts.CheckNonEmpty(path, nameof(path));
if (!File.Exists(path))
{
throw Contracts.ExceptParam(nameof(path), "File does not exist at path: {0}", path);
}
// REVIEW: it is almost always a mistake to have a 'trainable' text loader here.
// Therefore, we are going to disallow data sample.
return(TextLoader.CreateTextLoader <TInput>(CatalogUtils.GetEnvironment(catalog), hasHeader, separatorChar,
allowQuoting, allowSparse, trimWhitespace).Load(new MultiFileSource(path)));
}
/// <summary>
/// Create a text loader <see cref="TextLoader"/> by inferencing the dataset schema from a data model type.
/// </summary>
/// <param name="catalog">The <see cref="DataOperationsCatalog"/> catalog.</param>
/// <param name="options">Defines the settings of the load operation. Defines the settings of the load operation. No need to specify a Columns field,
/// as columns will be infered by this method.</param>
/// <param name="dataSample">The optional location of a data sample. The sample can be used to infer information
/// about the columns, such as slot names.</param>
public static TextLoader CreateTextLoader <TInput>(this DataOperationsCatalog catalog,
TextLoader.Options options,
IMultiStreamSource dataSample = null)
=> TextLoader.CreateTextLoader <TInput>(CatalogUtils.GetEnvironment(catalog), options, dataSample);