| angle | Angle between two subspaces |
| hier.phd.nt | Main hierarchical SDR fitting function |
| hier.sphd | Main hierarchical sufficient dimension reduction fitting function |
| phd | PHD SDR fitting function |
| plot.hier_sdr_fit | Plotting hierarchical SDR models |
| projnorm | Norm of difference of projections |
| semi.phd | Semiparametric PHD SDR fitting function |
| simulate_data | Simulate data with hierarchical subspaces |