R/FitCalibCoxRSInts.R

Defines functions FitCalibCoxRSInts

Documented in FitCalibCoxRSInts

  #### FitCalibCoxRSInts function
# Unlike FitCalibCoxRS, this function only estimate the model in certain given number of points, and not in each risk set time
## The function takes the following
## pts.for.ints: the points defining the intervals (first one has to be zero)  - should be sorted from zero up
###
# The function returns a list of cox fits for interval-censored time to event data, 
#' @title Fitting Proportional Hazards Grouped Risk-Set Calibration Models with Covariates
#' @description \code{FitCalibCoxRSInts} fits proportional hazards grouped risk-set calibration models for time-to-exposure from interval-censored data with covariates. The exposure is a binary covariate measured
#' in intermittent times. The covariates (\code{Q}) are associated with the time-to-exposure. Unlike \code{FitCalibCoxRS}, this function fits a calibration model
#' at each of the given points for \code{pts.for.ints}. 
#' @param w A matrix of time points when measurements on the binary covariate were obtained.
#' @param w.res A matrix of measurement results of the binary covariate. It corresponds to the time points in \code{w}
#' @param Q Matrix of covariates for PH calibration model
#' @param hz.times Times used for calculating the baseline hazard function of a PH calibration model
#' @param n.int The number of interior knots to be used, see \code{ICsurv::fast.PH.ICsurv.EM}, Default: 5
#' @param order the order of the basis functions. See \code{ICsurv::fast.PH.ICsurv.EM}, Default: 2
#' @param tm Vector of observed main event time or censoring time
#' @param event Vector of censoring indicators. \code{1} for event \code{0} for censored
#' @param pts.for.ints Points defining the intervals for grouping risk-sets (first one has to be zero). Should be sorted from zero up.
#' \code{pts.for.ints} is used only for \code{FitCalibCoxRSInts}.
#' @return A list of Cox PH model fits, each supplemented with the knots and order used for the I-splines.
#' @details In case of an error in the model-fitting at a certain time point, a proportional hazards calibration 
#' model (for all the data) is fitted and used for that time point.
#' @examples 
#' set.seed(2) 
#' sim.data <- ICcalib:::SimCoxIntervalCensCox(n.sample = 50, lambda = 0.1, 
#'                                             alpha = 0.25, beta0 = log(0.2),
#'                                             gamma.q = c(log(0.75), log(2.5)), 
#'                                             gamma.z = log(1.5), mu = 0.2, 
#'                                             n.points = 2)
#' # The baseline hazard for the calibration model is calculated in observation times
#' cox.hz.times <- sort(unique(sim.data$obs.tm)) 
#' # Fit proprtional hazards grouped risk-sets calibration models
#' calib.ph.rs.fit <- FitCalibCoxRSInts(w = sim.data$w, w.res = sim.data$w.res, Q = sim.data$Q, 
#'                                      hz.times = cox.hz.times, tm = sim.data$obs.tm, 
#'                                      event = sim.data$delta, pts.for.ints = seq(0, 3, 1.5),
#'                                      n.int = 5, order = 2)
#' # Below is a more time consuming option (no grouping of risk-sets)
#' # FitCalibCoxRS(w = sim.data$w, w.res = sim.data$w.res, Q = sim.data$Q, 
#' #                hz.times = cox.hz.times, obs.tm = sim.data$obs.tm, 
#' #               event = sim.data$delta, n.int = 5, order = 1)
# \dontrun{
# if(interactive()){
#  #EXAMPLE1
#  }
# }
#' @seealso 
#'  \code{\link[ICsurv]{fast.PH.ICsurv.EM}},  \code{\link[ICcalib]{FitCalibCox}}
#' @rdname FitCalibCoxRSInts
#' @export 
#' @importFrom ICsurv fast.PH.ICsurv.EM
FitCalibCoxRSInts<- function(w, w.res, Q, hz.times, n.int = 5, order = 2 , tm, event, pts.for.ints)
{
n.fail <- 0
n.int.org <- n.int
if (pts.for.ints[1] != 0) {pts.for.ints <- c(0, pts.for.ints)}
r <- length(pts.for.ints)
event.index <- which(event==1)
lr.for.fit.all <- as.data.frame(FindIntervalCalibCPP(w = w, wres = w.res))
Q.all <- Q
all.fit.cox.res <- list()
for (j in 1:r)
{
  n.int <- n.int.org
  point <- pts.for.ints[j]
  # Keep only observations in the risk set
  lr.for.fit <- lr.for.fit.all[tm>=point, ]  
  Q <- Q.all[tm>=point, ]
  # Take out noninformative observations
  Q <- Q[!(lr.for.fit[,1]==0 & lr.for.fit[,2]==Inf),]
  lr.for.fit <- lr.for.fit[!(lr.for.fit[,1]==0 & lr.for.fit[,2]==Inf),]
  #
  colnames(lr.for.fit) <- c("left","right")
  d1 <- lr.for.fit[,1]==0
  d3 <- lr.for.fit[,2]==Inf
  d2 <- 1 - d1 - d3
  fit.cox.point <- tryCatch(ICsurv::fast.PH.ICsurv.EM(d1 = d1, d2 = d2, d3 = d3,Li = lr.for.fit[,1],
                                        Ri = lr.for.fit[,2], n.int = n.int, order = order,  Xp = Q, g0 =rep(1,n.int + order), b0 = rep(0,ncol(Q)),
                                        t.seq = hz.times, tol = 0.001), error = function(e){e})
   while(inherits(fit.cox.point, "error") & n.int >= 2) { 
     n.int <- n.int - 1
     fit.cox.point <- tryCatch(ICsurv::fast.PH.ICsurv.EM(d1 = d1, d2 = d2, d3 = d3,Li = lr.for.fit[,1],
                                           Ri = lr.for.fit[,2], n.int = n.int, order = order,  Xp = Q, g0 =rep(1,n.int + order), b0 = rep(0,ncol(Q)),
                                           t.seq = hz.times, tol = 0.001), error = function(e){e})
   }
  if (inherits(fit.cox.point, "error")) {
    fit.cox.point <- FitCalibCox(w = w, w.res = w.res, Q = Q.all, hz.times = hz.times, n.int = n.int.org, order = order)
    warning(paste("In point", point, "Calibration was used instead of risk set calibration"),immediate. = T)
    n.fail <- n.fail + 1
  }   else {
    if (max(abs(fit.cox.point$b)) > 3.5)
    {
      fit.cox.point <- FitCalibCox(w = w, w.res = w.res, Q = Q.all, hz.times = hz.times, n.int = n.int.org, order = order)
      warning(paste("In point", point, "Calibration was used instead of risk set calibration"),immediate. = T)
      n.fail <- n.fail + 1
    } else {
    ti <- c(lr.for.fit[d1 == 0,1], lr.for.fit[d3 == 0,2])
    fit.cox.point$knots <-   seq(min(ti) - 1e-05,  max(ti) + 1e-05, length.out = (n.int + 2))
    fit.cox.point$order <- order
  }}
  all.fit.cox.res[[j]] <- fit.cox.point
}
if (n.fail > 0) {warning(paste("In ", round(100*n.fail/r,0), "% of the event times there were no sufficient data to fit a risk-set calibration model"))}
if (n.fail/r > 0.5) stop("In more of 50% of the intervals there were no sufficient data to fit a risk-set calibration model")
return(all.fit.cox.res)
}

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ICcalib documentation built on Aug. 1, 2018, 9:01 a.m.