| innerProduct | Pairwise inner product for L^2 functions | 
| mrct | Minimum regularized covariance trace estimator | 
| mrct.ise | Integrated square error | 
| mrct.plot | Plot function for result from 'mrct()' | 
| mrct.rgauss | Random sample from Gaussian process | 
| mrct.sparse | Sparse minimum regularized covariance trace estimator | 
| mrct.sparse.plot | Plot function for result from 'mrct.sparse()' |