Provides nonparametric and Cox-type regression methods for analyzing
zero-truncated recurrent event data with supplementary information. Key features include
estimating rate and mean functions under nonparametric marginal models; estimating time-constant
regression coefficients under standard and stratified Andersen-Gill (AG) models; and estimating
time-varying covariate effects under stratified and nonstratified Cox-type models. Standard
errors (SEs) are estimated using sandwich-based variance estimators for nonstratified models and
resampling-based procedures for stratified models. For further details, see Chen, Hu, and
Rosychuk (2026)