private static void ReadMatrix(ref Variable vi, UInt32 length, BinaryReader matrixStream)
{
Tag t;
long offset = matrixStream.BaseStream.Position;
//Array flags
//Will always be too large to be in small data format, so not checking t.data
t = MatfileHelper.ReadTag(matrixStream);
UInt32 flagsClass = matrixStream.ReadUInt32();
byte flags = (byte)(flagsClass >> 8) ;
if ((flags & 0x80) == 0x80)
throw new IOException("Complex numbers not supported");
vi.dataType = MatfileHelper.parseArrayType((byte)flagsClass);
matrixStream.ReadUInt32();//unused flags
//Dimensions - There are always 2 dimensions, so this
//tag will never be of small data format, i.e. not checking for t.data
t = MatfileHelper.ReadTag(matrixStream);
int[] arrayDimensions = new int[t.length / MatfileHelper.MatlabBytesPerType(t.dataType)];
int elements = 1;
for (int i = 0; i < arrayDimensions.Length; i++)
{
int dimension = (int)matrixStream.ReadUInt32();
arrayDimensions[arrayDimensions.Length - i - 1] = dimension;
elements *= dimension;
}
//Don't keep single dimensions
arrayDimensions = arrayDimensions.Where(x => x > 1).ToArray();
//If by doing this, we end up without dimensions, it means we had a 1x...x1 array.
//We need at least 1 dimension to instantiate the final array, so...
if (arrayDimensions.Length == 0)
arrayDimensions = new int[1] { 1 };
//Array name
t = MatfileHelper.ReadTag(matrixStream);
if (t.data != null)
{
sbyte[] varname = t.data as sbyte[];
vi.name = Encoding.UTF8.GetString(Array.ConvertAll(varname, x => (byte)x));
} else {
byte[] varname = matrixStream.ReadBytes((int)t.length);
vi.name = Encoding.UTF8.GetString(varname);
MatfileHelper.AdvanceTo8ByteBoundary(matrixStream);
}
//Read and reshape data
t = MatfileHelper.ReadTag(matrixStream);
if (t.length / MatfileHelper.MatlabBytesPerType(t.dataType) != elements)
throw new IOException("Read dimensions didn't correspond to header dimensions");
Array readBytes;
if (t.data == null)
readBytes = MatfileHelper.CastToMatlabType(vi.dataType, matrixStream.ReadBytes((int)t.length));
else
readBytes = (Array)t.data;
Array reshapedData = Array.CreateInstance(vi.dataType, arrayDimensions);
if (t.dataType != vi.dataType) //This happens when matlab choses to store the data in a smaller datatype when the values permit it
{
Array linearData = Array.CreateInstance(vi.dataType, readBytes.Length);
Array.Copy(readBytes, linearData, readBytes.Length);
Buffer.BlockCopy(linearData, 0, reshapedData, 0, linearData.Length * MatfileHelper.MatlabBytesPerType(vi.dataType));
vi.dataType = t.dataType;
}
else //Readbytes is already in the correct type
Buffer.BlockCopy(readBytes, 0, reshapedData, 0, readBytes.Length * MatfileHelper.MatlabBytesPerType(vi.dataType));
if(reshapedData.Length == 1)
vi.data = reshapedData.GetValue(0);
else
vi.data = reshapedData;
//Move on in case the data didn't end on a 64 byte boundary
matrixStream.BaseStream.Seek(offset + length, SeekOrigin.Begin);
}
private void ReadVariables()
{
Variables = new Dictionary<string, Variable>();
while(readStream.BaseStream.Position < readStream.BaseStream.Length)
{
Variable v = new Variable();
Tag t = MatfileHelper.ReadTag(readStream);
if(t.dataType == null)
throw new Exception("Not an array, don't know what to do with this stuff");
else if (t.dataType.Equals(typeof(Array))) //We use Array to indicate MiMatrix
{
ReadMatrix(ref v, t.length, readStream);
} else if (t.dataType.Equals(typeof(ZlibStream)))
{
byte[] compressed = readStream.ReadBytes((int)t.length);
byte[] decompressed = ZlibStream.UncompressBuffer(compressed);
MemoryStream m = new MemoryStream(decompressed);
BinaryReader br = new BinaryReader(m);
Tag ct = MatfileHelper.ReadTag(br);
ReadMatrix(ref v, ct.length, br);
}
else
throw new Exception("Not an array, don't know what to do with this stuff");
Variables.Add(v.name, v);
}
}
