/// <summary>
/// Read a data view from a text file using <see cref="TextLoader"/>.
/// </summary>
/// <param name="catalog">The catalog.</param>
/// <param name="columns">The columns of the schema.</param>
/// <param name="advancedSettings">The delegate to set additional settings</param>
/// <param name="path">The path to the file</param>
/// <returns>The data view.</returns>
public static IDataView ReadFromTextFile(this DataLoadSaveOperations catalog,
TextLoader.Column[] columns, string path, Action <TextLoader.Arguments> advancedSettings = null)
{
Contracts.CheckNonEmpty(path, nameof(path));
var env = catalog.GetEnvironment();
// REVIEW: it is almost always a mistake to have a 'trainable' text loader here.
// Therefore, we are going to disallow data sample.
var reader = new TextLoader(env, columns, advancedSettings, dataSample: null);
return(reader.Read(new MultiFileSource(path)));
}
/// <summary>
/// Save the data view as text.
/// </summary>
/// <param name="catalog">The catalog.</param>
/// <param name="data">The data view to save.</param>
/// <param name="stream">The stream to write to.</param>
/// <param name="separator">The column separator.</param>
/// <param name="headerRow">Whether to write the header row.</param>
/// <param name="schema">Whether to write the header comment with the schema.</param>
/// <param name="keepHidden">Whether to keep hidden columns in the dataset.</param>
public static void SaveAsText(this DataLoadSaveOperations catalog, IDataView data, Stream stream,
char separator = '\t', bool headerRow = true, bool schema = true, bool keepHidden = false)
{
Contracts.CheckValue(catalog, nameof(catalog));
Contracts.CheckValue(data, nameof(data));
Contracts.CheckValue(stream, nameof(stream));
var env = catalog.GetEnvironment();
var saver = new TextSaver(env, new TextSaver.Arguments {
Separator = separator.ToString(), OutputHeader = headerRow, OutputSchema = schema
});
using (var ch = env.Start("Saving data"))
DataSaverUtils.SaveDataView(ch, saver, data, stream, keepHidden);
}