| CD4 | CD4 cell counts | 
| FPCscoreLSE | Least square estimates of functional principal component scores | 
| GenDataKL | Generate functional/longitudinal data via KL expansion | 
| GetGCVbw1D | Bandwidth selection through GCV for one-dimension cases | 
| GetGCVbw2D | Bandwidth selection through GCV for two-dimension cases | 
| kernfun | Kernel Functions | 
| KFPCA | Kendall Functional Principal Component Analysis (KFPCA) for sparse design | 
| KFPCA_reg | Kendall Functional Principal Component Analysis (KFPCA) for dense and regular design | 
| MeanEst | Local linear estimates of mean function | 
| predict.KFPCA | Predict FPC scores | 
| SparsePlot | Sparse plot |