/// <summary>
/// Gets song data via song_id
/// </summary>
/// <param name="song_id">song_id in DataBase</param>
public TransferDataFFT GetSongData(int song_id)
{
TransferDataSong tds = new TransferDataSong();
TransferDataFFT tdf = new TransferDataFFT();
string query = "SELECT data FROM songs WHERE song_id=" + song_id;
using (SQLiteConnection connection = new SQLiteConnection(cb.ConnectionString))
{
connection.Open();
using (SQLiteCommand command = new SQLiteCommand(connection))
{
command.CommandText = query;
command.CommandType = CommandType.Text;
using (SQLiteDataReader Reader = command.ExecuteReader())
{
while (Reader.Read())
{
int DataRowNumber = Reader.GetOrdinal("data");
byte[] buffer = new byte[Reader.GetBytes(DataRowNumber, 0, null, 0, int.MaxValue)];
Reader.GetBytes(DataRowNumber, 0, buffer, 0, buffer.Length);
tds.data = buffer;
tdf = tds.DeserializeData();
}
}
}
}
return(tdf);
}
public int[] GetSongsBySpectra(FrequencyState[] State, int NumberOfSongsToShow = 20)
{
List <TransferDataSong> list = db.GetAllRecords();
int size = list.Count;
TransferDataFFT[] arr = new TransferDataFFT[size];
int[] Score = new int[size];
int[] indexes = new int[size];
for (int i = 0; i < size; i++)
{
arr[i] = list[i].DeserializeData();
indexes[i] = list[i].id;
}
int FreqCount = (arr[0].meanF.Length - 1) / State.Length;
for (int j = 0; j < State.Length; j++)
{
if (State[j] != FrequencyState.Off)
{
double sum;
int[] ind = Enumerable.Range(0, size).ToArray();
double[] Freq = new double[size];
int le = j * FreqCount, re = le + FreqCount;
for (int i = 0; i < size; i++)
{
sum = 0;
for (int k = le; k < re; k++)
{
sum += arr[i].meanF[k] / FreqCount;
}
Freq[i] = sum;
}
if (State[j] == FrequencyState.Min)
{
Array.Sort(Freq, ind);
for (int i = 0; i < size; i++)
{
Score[ind[i]] += size - i - 1;
}
}
else
{
Array.Sort(Freq, ind);
for (int i = 0; i < size; i++)
{
Score[ind[i]] += i;
}
}
}
}
Array.Sort(Score, indexes);
Array.Reverse(indexes);
return(indexes.Take(NumberOfSongsToShow).ToArray());
}
public int[] GetSimilarSongs(int song_id, int MethodId = 1, int NumberOfSongsToShow = 20)
{
List <TransferDataSong> list = db.GetAllRecords();
int size = list.Count;
TransferDataFFT[] arr = new TransferDataFFT[size];
int[] indexes = new int[size];
for (int i = 0; i < size; i++)
{
arr[i] = list[i].DeserializeData();
indexes[i] = list[i].id;
}
int song_number = Array.IndexOf(indexes, song_id);
double[] sim = new double[size];
for (int i = 0; i < size; i++)
{
sim[i] = GetSimilarity(arr[i], arr[song_number], MethodId);
}
Array.Sort(sim, indexes);
return(indexes.Skip(1).Take(NumberOfSongsToShow).ToArray());
}
public double GetSimilarity(TransferDataFFT sample1, TransferDataFFT sample2, int MethodId)
{
double res = 0;
int FreqNumber = sample1.meanF.Length;
switch (MethodId)
{
case 1:
for (int i = 0; i < FreqNumber; i++)
{
res += Math.Pow(sample1.meanF[i] - sample2.meanF[i], 2) / Math.Pow(sample1.meanF[i] + sample2.meanF[i], 2);
}
break;
case 2:
for (int i = 0; i < FreqNumber; i++)
{
res += Math.Pow(sample1.meanF[i] - sample2.meanF[i], 2) / Math.Pow(sample1.meanF[i] + sample2.meanF[i], 2) +
Math.Pow(sample1.medianF[i] - sample2.medianF[i], 2) / Math.Pow(sample1.medianF[i] + sample2.medianF[i], 2) +
Math.Pow(sample1.stdF[i] - sample2.stdF[i], 2) / Math.Pow(sample1.stdF[i] + sample2.stdF[i], 2);
}
break;
case 3:
res = 1;
for (int i = 0; i < FreqNumber; i++)
{
if (sample1.meanF[i] > sample2.meanF[i])
{
res *= sample1.meanF[i] / sample2.meanF[i];
}
else
{
res *= sample2.meanF[i] / sample1.meanF[i];
}
}
break;
case 4:
int size = sample1.meanF.Length;
res = 1;
for (int i = 0; i < size; i++)
{
if (sample1.meanF[i] > sample2.meanF[i])
{
res *= sample1.meanF[i] / sample2.meanF[i];
}
else
{
res *= sample2.meanF[i] / sample1.meanF[i];
}
}
int[] indexes1 = Enumerable.Range(1, size).ToArray();
int[] indexes2 = Enumerable.Range(1, size).ToArray();
double[] sig1 = sample1.meanF;
double[] sig2 = sample2.meanF;
Array.Sort(sig1, indexes1);
Array.Sort(sig2, indexes2);
int sum = 1;
for (int i = 0; i < size; i++)
{
sum += Math.Abs(indexes1[i] - indexes2[i]);
}
res = res * sum;
break;
}
return(res);
}