Method readMatrix

src/main/java/com/jmatio/io/MatFileReader.java:859–1241

Reads miMATRIX from from input stream. If reading was not finished (which is normal for filtered results) returns null . Modifies buf position to the position when reading finished. Uses recursive processing for some ML data types. @param buf - input byte b

(ByteBuffer buf, boolean isRoot)

	 * @throws IOException when error occurs while reading the buffer.
	 */
	private MLArray readMatrix(ByteBuffer buf, boolean isRoot) throws IOException {
		//result
		MLArray mlArray;
		ISMatTag tag;

		//read flags
		int[] flags = readFlags(buf);
		int attributes = (flags.length != 0) ? flags[0] : 0;
		int nzmax = (flags.length != 0) ? flags[1] : 0;
		int type = attributes & 0xff;

		//read Array dimension
		int[] dims = readDimension(buf);

		//read array Name
		String name = readName(buf, matFileHeader);

		//if this array is filtered out return immediately
		if (isRoot && !filter.matches(name)) {
			return null;
		}

		//read data >> consider changing it to stategy pattern
		switch (type) {
		case MLArray.mxSTRUCT_CLASS:

			MLStructure struct = new MLStructure(name, dims, attributes);

			//field name lenght - this subelement always uses the compressed data element format
			new ISMatTag(buf);
			int maxlen = buf.getInt(); //maximum field length

			//////  read fields data as Int8
			tag = new ISMatTag(buf);
			//calculate number of fields
			int numOfFields = tag.size / maxlen;

			String[] fieldNames = new String[numOfFields];
			for (int i = 0; i < numOfFields; i++) {
				byte[] names = new byte[maxlen];
				buf.get(names);
				fieldNames[i] = zeroEndByteArrayToString(names);
			}
			buf.position(buf.position() + tag.padding);
			//read fields
			for (int index = 0; index < struct.getM() * struct.getN(); index++) {
				for (int i = 0; i < numOfFields; i++) {
					//read matrix recursively
					tag = new ISMatTag(buf);

					MLArray array;
					if (tag.size > 0) {
						array = readMatrix(buf, false);
					} else {
						array = new MLEmptyArray();
					}
					array.name = fieldNames[i];
					struct.setField(fieldNames[i], array, index);