WA_cv: K-fold cross-validation for WA configuration selection

In WAreg: While-Alive Regression for Composite Endpoints with Cluster-Robust Inference

K-fold cross-validation for WA configuration selection

Description

Runs K-fold CV over a grid of basis types, degrees, interior-knot counts, and link functions. For each configuration, fits the model on K-1 folds and accumulates the prediction error (PE) on the held-out fold using WA_PE() (IPCW computed on the training subjects).

Usage

WA_cv(
  formula,
  data,
  id,
  cluster = NULL,
  basis_set = c("il", "pl", "bz"),
  degree_vec = 1:2,
  n_int_vec = c(0, 2, 4),
  knot_scheme = c("equidist", "quantile"),
  link_set = c("log"),
  time_range = NULL,
  tau_grid = NULL,
  w_recur,
  w_term,
  ipcw = c("cox", "km"),
  ipcw_formula = ~1,
  K = 5,
  seed = 1L,
  verbose = TRUE
)

Arguments

formula	A Surv(time, status) ~ RHS formula; see WA_fit.
data	Long-format data frame; see WA_fit.
id	Character scalar; subject ID column name; see WA_fit.
cluster	Optional character scalar; cluster column name; see WA_fit.
basis_set	Character vector of candidate bases.
degree_vec	Integer vector of candidate degrees.
n_int_vec	Integer vector of interior-knot counts; 0 means boundaries only.
knot_scheme	"equidist" or "quantile" to construct interior knots.
link_set	Character vector of candidate links (subset of c("log","identity")).
time_range	Optional numeric length-2 vector c(tmin, tmax). If NULL, inferred from data.
tau_grid	Optional numeric vector; if NULL, a default dense grid over time_range is created.
w_recur	recurrent-event weights
w_term	Numeric scalar; terminal-event weight; see WA_fit.
ipcw	IPCW method ("cox" or "km") for PE computation.
ipcw_formula	One-sided RHS formula for IPCW Cox model (if ipcw="cox").
K	Number of folds.
seed	RNG seed for fold assignment.
verbose	Logical; show a text progress bar and per-fold messages.

Value

A data frame with columns: basis, degree, n_int, link, and aggregated PE. Lower PE is better.

WAreg documentation built on March 6, 2026, 5:07 p.m.