C# StreamReader.TryReadLine方法代码示例

        /// <summary>
        /// Constructor
        /// </summary>
        /// <param name="wordNetDirectory">Path to WorNet directory (the one with the data and index files in it)</param>
        /// <param name="inMemory">Whether or not to store all data in memory. In-memory storage requires quite a bit of space
        /// but it is also very quick. The alternative (false) will cause the data to be searched on-disk with an efficient
        /// binary search algorithm.</param>
        public WordNetEngine(string wordNetDirectory, bool inMemory)
        {
            _wordNetDirectory = wordNetDirectory;
            _inMemory = inMemory;
            _posIndexWordSearchStream = null;
            _posSynSetDataFile = null;

            if (!System.IO.Directory.Exists(_wordNetDirectory))
                throw new DirectoryNotFoundException("Отсутствует WordNet директория:  " + _wordNetDirectory);

            // get data and index paths
            string[] dataPaths = new string[]
            {
                Path.Combine(_wordNetDirectory, "data.adj"),
                Path.Combine(_wordNetDirectory, "data.adv"),
                Path.Combine(_wordNetDirectory, "data.noun"),
                Path.Combine(_wordNetDirectory, "data.verb")
            };

            string[] indexPaths = new string[]
            {
                Path.Combine(_wordNetDirectory, "index.adj"),
                Path.Combine(_wordNetDirectory, "index.adv"),
                Path.Combine(_wordNetDirectory, "index.noun"),
                Path.Combine(_wordNetDirectory, "index.verb")
            };

            // make sure all files exist
            foreach (string path in dataPaths.Union(indexPaths))
                if (!System.IO.File.Exists(path))
                    throw new FileNotFoundException("Failed to find WordNet file:  " + path);

            #region index file sorting
            string sortFlagPath = Path.Combine(_wordNetDirectory, ".sorted_for_dot_net");
            if (!System.IO.File.Exists(sortFlagPath))
            {
                /* make sure the index files are sorted according to the current sort order. the index files in the
                 * wordnet distribution are sorted in the order needed for (presumably) the java api, which uses
                 * a different sort order than the .net runtime. thus, unless we resort the lines in the index 
                 * files, we won't be able to do a proper binary search over the data. */
                foreach (string indexPath in indexPaths)
                {
                    // create temporary file for sorted lines
                    string tempPath = Path.GetTempFileName();
                    StreamWriter tempFile = new StreamWriter(tempPath);

                    // get number of words (lines) in file
                    int numWords = 0;
                    StreamReader indexFile = new StreamReader(indexPath);
                    string line;
                    while (indexFile.TryReadLine(out line))
                        if (!line.StartsWith(" "))
                            ++numWords;

                    // get lines in file, sorted by first column (i.e., the word)
                    Dictionary<string, string> wordLine = new Dictionary<string, string>(numWords);
                    indexFile = new StreamReader(indexPath);
                    while (indexFile.TryReadLine(out line))
                        // write header lines to temp file immediately
                        if (line.StartsWith(" "))
                            tempFile.WriteLine(line);
                        else
                        {
                            // trim useless blank spaces from line and map line to first column
                            line = line.Trim();
                            wordLine.Add(line.Substring(0, line.IndexOf(' ')), line);
                        }

                    // get sorted words
                    List<string> sortedWords = new List<string>(wordLine.Count);
                    sortedWords.AddRange(wordLine.Keys);
                    sortedWords.Sort();

                    // write lines sorted by word
                    foreach (string word in sortedWords)
                        tempFile.WriteLine(wordLine[word]);

                    tempFile.Close();

                    // replace original index file with properly sorted one
                    System.IO.File.Delete(indexPath);
                    System.IO.File.Move(tempPath, indexPath);
                }

                // create flag file, indicating that we've sorted the data
                StreamWriter sortFlagFile = new StreamWriter(sortFlagPath);
                sortFlagFile.WriteLine("This file serves no purpose other than to indicate that the WordNet distribution data in the current directory has been sorted for use by the .NET API.");
                sortFlagFile.Close();
            }
            #endregion

            #region engine init
            if (inMemory)
//.........这里部分代码省略.........

        private Dictionary<int, float> GetPerClassWeights(StreamReader trainingInstancesReader)
        {
            Dictionary<int, int> classCount = new Dictionary<int, int>();
            string line;
            while (trainingInstancesReader.TryReadLine(out line))
            {
                int firstSpace = line.IndexOf(' ');
                if (firstSpace == -1)
                    firstSpace = line.Length;

                int classNum = int.Parse(line.Substring(0, firstSpace));
                classCount.EnsureContainsKey(classNum, typeof(int));
                classCount[classNum]++;
            }

            Dictionary<int, float> classWeight = new Dictionary<int, float>();
            int total = classCount.Values.Sum();
            foreach (int classNum in classCount.Keys)
                if (_libLinear.GetUnmappedLabel(classNum.ToString()) != PointPrediction.NullLabel)
                    classWeight.Add(classNum, (total - classCount[classNum]) / (float)classCount[classNum]);

            return classWeight;
        }