Running examples in 'SvyNom-Ex.R' failed
The error most likely occurred in:

> base::assign(".ptime", proc.time(), pos = "CheckExEnv")
> ### Name: svycox.validate
> ### Title: Validating a nomogram for a survey-weighted Cox model
> ### Aliases: svycox.validate
> ### Keywords: survival survey nomogram
> 
> ### ** Examples
> bootit=200
> library(survey)
Loading required package: grid
Loading required package: Matrix
Loading required package: survival

Attaching package: 'survey'

The following object is masked from 'package:graphics':

    dotchart

> library(rms)
Loading required package: Hmisc
Loading required package: lattice
Loading required package: Formula
Loading required package: ggplot2

Attaching package: 'Hmisc'

The following object is masked from 'package:survey':

    deff

The following objects are masked from 'package:base':

    format.pval, units

Loading required package: SparseM

Attaching package: 'SparseM'

The following object is masked from 'package:base':

    backsolve


Attaching package: 'rms'

The following object is masked from 'package:survey':

    calibrate

> data(noNA)
> dd=datadist(noNA)
> options(datadist="dd")
> dstr2=svydesign(id=~1, strata=~group, prob=~inv_weight, fpc=~ssize, data=noNA)
> mynom=svycox.nomogram(.design=dstr2, .model=Surv(survival,surv_cens)~ECOG+liver_only+Alb+Hb+Age+
+ Differentiation+Gt_1_m1site+lymph_only, .data=noNA, pred.at=24, fun.lab="Prob of 2 Yr OS")
> 
> cases=which(noNA$group=="long")
> controls=which(noNA$group=="<24")
> boot.index=matrix(NA,nrow(noNA),bootit)
> for(i in 1:bootit){
+ boot.index[,i]=c(sample(cases,replace=TRUE),sample(controls,replace=TRUE))
+ }
> myval=svycox.validate(boot.index,mynom,noNA)  
Warning: Using formula(x) is deprecated when x is a character vector of length > 1.
  Consider formula(paste(x, collapse = " ")) instead.
Warning: Using formula(x) is deprecated when x is a character vector of length > 1.
  Consider formula(paste(x, collapse = " ")) instead.
Error in terms.formula(formula, data = data) : 
  invalid model formula in ExtractVars
Calls: svycox.validate ... model.frame -> model.frame.default -> terms -> terms.formula
Execution halted