public void write_float32 (byte[] buffer, int index, float f) {
    int v = Float.floatToIntBits (f);
    buffer [index] = (byte) (v >> 24);
    index++;
    buffer [index] = (byte) (v >> 24);
    index++;
    buffer [index] = (byte) (v >> 16);
    index++;
    buffer [index] = (byte) (v >> 8);
    index++;
    buffer [index] = (byte) v;
    index++;
  }