Ejemplo n.º 1
0
        static List<DataItem> LoadData(int classLabel, string type, int numTopics)
        {
            MongoServer server = MongoServer.Create();
            MongoDatabase db = server.GetDatabase("docmodel");
            MongoCollection<BsonDocument> coll = db.GetCollection<BsonDocument>("ldamodel_" + type + "_" + classLabel + "_" + numTopics);
            MongoCursor<BsonDocument> cursor = coll.FindAll();
            List<DataItem> items = new List<DataItem>();
            foreach (BsonDocument doc in cursor)
            {
                DataItem item = new DataItem();
                items.Add(item);
                item.DataItemId = doc["DocID"].AsString;
                if (!doc["ClassLabels"].IsBsonNull)
                {
                    foreach (BsonValue cl in doc["ClassLabels"].AsBsonArray)
                    {
                        item.AddClassLabel(cl.AsInt32);
                    }
                }

                if (!doc["WordCounts"].IsBsonNull)
                {
                    foreach (BsonDocument kvp in doc["WordCounts"].AsBsonArray)
                    {
                        foreach (BsonElement e in kvp)
                        {
                            item.AddItem(e.Value.AsInt32, 1);
                        }
                    }
                }
                item.Normalize();
            }
            cursor = null;
            coll = null;
            db = null;
            server.Disconnect();
            return items;
        }
Ejemplo n.º 2
0
 public double Func(DataItem item, double[] theta)
 {
     double sum = 0;
     for (int j = 0; j < theta.Length; j++)
     {
         if (j == theta.Length - 1)
         {
             sum += theta[j];
         }
         else
         {
             sum += item.GetItemWeight(j) * theta[j];
         }
     }
     double func = 1.0 / (1.0 + Math.Exp(-sum));
     return func;
 }
Ejemplo n.º 3
0
 static void Test()
 {
     LogisticReg regression = new LogisticReg(2, 1, 1);
     List<DataItem> items = new List<DataItem>();
     StreamReader reader = new StreamReader(new FileStream("ex2data2.txt", FileMode.Open));
     string line;
     while ((line = reader.ReadLine()) != null)
     {
         string[] ss = line.Split(',');
         DataItem item = new DataItem();
         item.AddItem(0, double.Parse(ss[0]));
         item.AddItem(1, double.Parse(ss[1]));
         item.AddClassLabel(int.Parse(ss[2]));
         items.Add(item);
     }
     double[] theta = { 0, 0 };
     double r = regression.CostFunc(items, theta);
 }