added trace_sum for efficiency
Merge branch 'master' of github.com:SheffieldML/GPy
some messing with the linear algebra in sparse_GP. This should be more efficient... let's hope nothing breaks
more messing with the linear algebra in sparse_GP
Merge branch 'master' of github.com:SheffieldML/GPy
typo in comments
Merge branch 'master' of github.com:SheffieldML/GPy