| CorrR | This function obtains the correlation matrix of longitudinal data |
| cv.interep | k-folds cross-validation for interep |
| dat | simulated data for demonstrating the features of interep |
| dmcp | This function obtains the first derivative function of MCP (Minimax Concave Penalty) |
| interep | fit a generalized estimating equation with given lambda |
| reformat | This function changes the format of the longitudinal data from wide format to long format |