/// <summary>
/// Loads clusters from the specified level.
/// </summary>
/// <param name="level">Number of the level from where to load the data.</param>
/// <returns>Returns an array of vertices.</returns>
public Centre[] LoadClusters(int level)
{
// open input file
string fileName = GetNumberedFileName(level);
FileStream streamIn = new FileStream(fileName, FileMode.Open, FileAccess.Read, FileShare.Read);
BinaryReader fileIn = new BinaryReader(streamIn);
// read the number of coordinates each vertex has
ushort coordCount = fileIn.ReadUInt16();
int vertexSize = sizeof(double) * coordCount;
int clusterCentreSize = vertexSize + sizeof(long) + sizeof(int);
// determine the number of points in the file
long fileLengthExclHeader = streamIn.Length - sizeof(UInt16);
int vertexCount;
if (level == 0)
{
// zero level vertices without pointers to cluster members
vertexCount = (int)fileLengthExclHeader / vertexSize;
}
else
{
vertexCount = (int)fileLengthExclHeader / clusterCentreSize;
}
// prepare memory
Centre[] vertices = new Centre[vertexCount];
// load the data
if (level > 0)
{
for (int i = 0; i < vertexCount; i++)
{
vertices[i] = Centre.ReadBinary(fileIn, coordCount);
}
}
else
{
for (int i = 0; i < vertexCount; i++)
{
vertices[i] = Centre.ReadBinaryJustCoords(fileIn, coordCount);
}
}
// close input file
fileIn.Close();
streamIn.Close();
return(vertices);
}
/// <summary>
/// Loads all members of the given cluster.
/// </summary>
/// <param name="level">The level from where to load the members (one level lower than the cluster centre).</param>
/// <param name="startIndex">Index of the first cluster member.</param>
/// <param name="count">Number of the cluster members.</param>
/// <returns>Returns an array of cluster vertices.</returns>
public Centre[] ExpandCluster(int level, long startIndex, int count)
{
// open input file
string fileName = GetNumberedFileName(level);
FileStream streamIn = new FileStream(fileName, FileMode.Open, FileAccess.Read, FileShare.Read);
BinaryReader fileIn = new BinaryReader(streamIn);
// read the number of coordinates each vertex has
ushort coordCount = fileIn.ReadUInt16();
// seek to the appropriate cluster
streamIn.Seek(startIndex, SeekOrigin.Begin);
// prepare memory
Centre[] clusterMembers = new Centre[count];
// load the cluster members
if (level > 0)
{
for (int i = 0; i < count; i++)
{
clusterMembers[i] = Centre.ReadBinary(fileIn, coordCount);
}
}
else
{
for (int i = 0; i < count; i++)
{
clusterMembers[i] = Centre.ReadBinaryJustCoords(fileIn, coordCount);
}
}
// close input file
fileIn.Close();
streamIn.Close();
return(clusterMembers);
}
