Running examples in ‘PermAlgo-Ex.R’ failed
The error most likely occurred in:

> base::assign(".ptime", proc.time(), pos = "CheckExEnv")
> ### Name: PermAlgo-package
> ### Title: Generate Event Times Conditional On Time-Dependent Covariates
> ### Aliases: PermAlgo-package PermAlgo
> ### Keywords: survival
> 
> ### ** Examples
> 
> 
> # Example - Generating adverse event conditional on use
> # of prescription drugs
> 
> # Prepare the matrice of covariate (Xmat)
> # Here we simulate daily exposures to 2 prescription drugs over a
> # year. Drug prescriptions can start any day of follow-up, and their
> # duration is a multiple of 7 days. There can be multiple prescriptions
> # for each individuals over the year and interuptions of drug use in
> # between.
> 
> # Additionaly, there is a time-independant binary covarite (sex).
> 
> n=500 # subjects
> m=365 # days
> 
> # Generate the matrix of three covariate, in a 'long' format.
> Xmat=matrix(ncol=3, nrow=n*m)
> 
> # time-independant binary covariate
> Xmat[,1] <- rep(rbinom(n, 1, 0.3), each=m)
> 
> # Function to generate an individual time-dependent exposure history
> # e.g. generate prescriptions of different durations and doses.
> TDhist <- function(m){
+   start <- round(runif(1,1,m),0) # individual start date
+   duration <-  7 + 7*rpois(1,3) # in weeks
+   dose <-  round(runif(1,0,10),1) 
+   vec <- c(rep(0, start-1), rep(dose, duration))
+   while (length(vec)<=m){
+     intermission <- 21 + 7*rpois(1,3) # in weeks
+     duration <-  7 + 7*rpois(1,3) # in weeks
+     dose <-  round(runif(1,0,10),1)
+     vec <- append(vec, c(rep(0, intermission), rep(dose, duration)))}
+   return(vec[1:m])}
> 
> # create TD var
> Xmat[,2] <- do.call("c", lapply(1:n, function(i) TDhist(m)))
> Xmat[,3] <- do.call("c", lapply(1:n, function(i) TDhist(m)))
> 
> # genereate vectors of event and censoring times prior to calling the
> # function for the algorithm
> 
> eventRandom <- round(rexp(n, 0.012)+1,0)
> censorRandom <- round(runif(n, 1,870),0)
> 
> # Generate the survival data conditional on the three covariates
> 
> data <- permalgorithm(n, m, Xmat, XmatNames=c("sex", "Drug1", "Drug2"),
+ eventRandom = eventRandom, censorRandom=censorRandom, betas=c(log(2),
+ log(1.04), log(0.99)), groupByD=FALSE )
Error in seq.default(from = ip, along.with = J) : 
  object 'intn1' not found
Calls: permalgorithm -> .PermuteCovariateVectors -> seq -> seq.default
Execution halted