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
