| boot_km_ratio | Bootstrap CI for an SBW-weighted KM survival ratio |
| get_sbws_for_study | Study-level SBW weights: closed-form first, QP fallback if needed |
| get_weights_for_group_neg | Closed-form SBW group weights (negative weights allowed) |
| get_weights_for_group_nonneg | Nonnegative-QP SBW group weights, with clipping diagnostics |
| km_ratio_greenwood | Weighted KM survival ratio S1(t0)/S0(t0) with a Greenwood-based CI |
| plot.sbw_fit | Plot covariate balance before and after SBW weighting |
| sbw_estimate | Estimate a treatment effect from a fitted 'sbw_fit' object |
| sbw_estimate.sbw_fit | Estimate a treatment effect from a fitted 'sbw_fit' object |
| sbw_weights | Fit stable balancing weights for a two-arm study (design stage) |
| summary.sbw_fit | Summarize an 'sbw_fit': balance table and weight diagnostics |