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

> base::assign(".ptime", proc.time(), pos = "CheckExEnv")
> ### Name: gsBinomialExact
> ### Title: 3.4: One-Sample Binomial Routines
> ### Aliases: gsBinomialExact print.gsBinomialExact plot.gsBinomialExact
> ###   binomialSPRT plot.binomialSPRT nBinomial1Sample
> ### Keywords: design
> 
> ### ** Examples
> 
> 
> zz <- gsBinomialExact(k=3,theta=seq(0,1,0.1), n.I=c(12,24,36),
+         a=c(-1, 0, 11),  b=c( 5, 9, 12))
> 
> # let's see what class this is
> class(zz)
[1] "gsBinomialExact" "gsProbability"  
> 
> # because of "gsProbability" class above, following is equivalent to 
> # print.gsProbability(zz)
> zz
              Bounds
  Analysis   N   a   b
         1  12  -1   5
         2  24   0   9
         3  36  11  12

Boundary crossing probabilities and expected sample size assume
any cross stops the trial

Upper boundary (power or Type I Error)
          Analysis
  Theta      1      2      3  Total E{N}
    0.0 0.0000 0.0000 0.0000 0.0000 24.0
    0.1 0.0043 0.0002 0.0001 0.0045 34.9
    0.2 0.0726 0.0155 0.0168 0.1048 34.0
    0.3 0.2763 0.0993 0.1164 0.4921 28.2
    0.4 0.5618 0.1782 0.1362 0.8762 20.4
    0.5 0.8062 0.1372 0.0463 0.9896 15.0
    0.6 0.9427 0.0519 0.0052 0.9998 12.8
    0.7 0.9905 0.0093 0.0002 1.0000 12.1
    0.8 0.9994 0.0006 0.0000 1.0000 12.0
    0.9 1.0000 0.0000 0.0000 1.0000 12.0
    1.0 1.0000 0.0000 0.0000 1.0000 12.0

Lower boundary (futility or Type II Error)
          Analysis
  Theta 1      2      3  Total
    0.0 0 1.0000 0.0000 1.0000
    0.1 0 0.0798 0.9157 0.9955
    0.2 0 0.0047 0.8905 0.8952
    0.3 0 0.0002 0.5077 0.5079
    0.4 0 0.0000 0.1238 0.1238
    0.5 0 0.0000 0.0104 0.0104
    0.6 0 0.0000 0.0002 0.0002
    0.7 0 0.0000 0.0000 0.0000
    0.8 0 0.0000 0.0000 0.0000
    0.9 0 0.0000 0.0000 0.0000
    1.0 0 0.0000 0.0000 0.0000
> # also plot (see also plots below for \code{binomialSPRT})
> # add lines using geom_line()
> plot(zz) + geom_line()
Error in grid.Call.graphics(C_setviewport, vp, TRUE) : 
  VECTOR_ELT() can only be applied to a 'list', not a 'double'
Calls: <Anonymous> ... lapply -> FUN -> push.vp.viewport -> grid.Call.graphics
Execution halted