R/EstimateSplineUnconstrainedNCC.R

In WCE: Weighted Cumulative Exposure Models

#' @importFrom survival clogit coxph.control coxph Surv
#' @importFrom stats as.formula logLik vcov
EstimateSplineUnconstrainedNCC <- function(DATA, n.knots, MatchedSet, covariates = NULL, Constrained = 'Right'){
  Dvar <- paste("D", 1:(n.knots+4), sep="")
  formula <- as.formula(paste("Event ~ strata(MatchedSet)+", paste(c(covariates, ''), collapse = "+"), paste(Dvar, collapse= "+")))
  cr <- clogit(formula, data=DATA)
  coefs<-cr$coefficients
  robSE<-data.frame(matrix(sqrt(diag(cr$var)), nrow=1))
  names(robSE) <- names(coefs)
  ll<-cr$loglik
  return(list(coefs=coefs, SE=robSE, ll=ll, Dvar=Dvar, vcovmat = vcov(cr)))}