Clean up normalisation code, does not affect any computed values.
Clean up normalisation code, does not affect any computed values.

SheffieldML/GPmat,SheffieldML/GPmat,TianpeiLuke/GPmat,SheffieldML/GPmat,TianpeiLuke/GPmat,TianpeiLuke/GPmat,TianpeiLuke/GPmat,SheffieldML/GPmat,TianpeiLuke/GPmat,SheffieldML/GPmat,SheffieldML/GPmat,TianpeiLuke/GPmat