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

> base::assign(".ptime", proc.time(), pos = "CheckExEnv")
> ### Name: qsreg
> ### Title: Quantile or Robust spline regression
> ### Aliases: qsreg
> ### Keywords: smooth
> 
> ### ** Examples
> 
> 
>      # fit a CV  quantile spline
>      fit50<- qsreg(rat.diet$t,rat.diet$con)
>      # (default is .5 so this is an estimate of the conditional median)
>      # control group of rats.
>      plot( fit50)
plot window will lay out plots in a 2 by 2 matrix 
>      predict( fit50)
 [1] 19.35821 19.17980 18.86549 19.28839 19.89899 21.03033 21.18050 21.50002
 [9] 22.79998 25.67707 26.19834 26.38231 24.51828 24.39903 24.84659 26.20001
[17] 26.64902 27.51194 27.55002 27.37895 27.01716 27.60002 27.80378 27.85000
[25] 27.62774 27.80000 28.15312 27.60002 27.44899 27.19901 27.79999 28.19900
[33] 27.99998 27.30002 27.89900 28.69897 28.28679 28.59999 27.50000
>      # predicted values at data points
>      xg<- seq(0,110,,50)
>      plot( fit50$x, fit50$y)
>      lines( xg, predict( fit50, xg))
> 
>      # A robust fit to rat diet data
>      # 
>      SC<- .5* median(abs((rat.diet$con- median(rat.diet$con))))
>      fit.robust<- qsreg(rat.diet$t,rat.diet$con, sc= SC)
>      plot( fit.robust)
plot window will lay out plots in a 2 by 2 matrix 
> 
>      # The global GCV function suggests little smoothing so 
>      # try the local
>      # minima with largest lambda instead of this default value.
>      # one should should consider redoing the three quantile fits in this
>      # example after looking at the cv functions and choosing a good value for
>      #lambda
>      # for example
>      lam<- fit50$cv.grid[,1]
>      tr<- fit50$cv.grid[,2]
>      # lambda close to df=6
>      lambda.good<- max(lam[tr>=6])
>      fit50.subjective<-qsreg(rat.diet$t,rat.diet$con, lam= lambda.good)
>      fit10<-qsreg(rat.diet$t,rat.diet$con, alpha=.1, nstep.cv=200)
>      fit90<-qsreg(rat.diet$t,rat.diet$con, alpha=.9, nstep.cv=200)
Error in qsreg(rat.diet$t, rat.diet$con, alpha = 0.9, nstep.cv = 200) : 
  NA/NaN/Inf in foreign function call (arg 5)
Execution halted