Commit for tona and nat.
Commit for tona and nat.

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