private static String asSeqString(
            final double[] data, 
            final int size, 
            final int length
    ) {
        StringBuilder out = new StringBuilder();
        //
        int off = 0;
        //
        for (int i = 0; i < length; i++) {
            if (i > 0) out.append(DEFAULT_VECTORDELIMITER);
            //
            for (int j = 0; j < size; j++) {
                if (j > 0) out.append(DEFAULT_VALUEDELIMITER);
                final double value = data[off++];
                out.append(value);
            }
        }
        //
        return out.toString();
    }