R Under development (unstable) (2026-02-10 r89394 ucrt) -- "Unsuffered Consequences"
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> options(digits=12)
> if(!require("BB"))stop("this test requires package BB.")
Loading required package: BB
> if(!require("setRNG"))stop("this test requires setRNG.")
Loading required package: setRNG
> 
> # Use a preset seed so test values are reproducable. 
> test.rng <- list(kind="Wichmann-Hill", normal.kind="Box-Muller", seed=c(979,1479,1542))
> old.seed <- setRNG(test.rng)
> 
> ##########
> cat("BB test chen.f ...\n")
BB test chen.f ...
> 
> chen.f <- function(x) {
+ v <- log(x) + exp(x)
+ f <- (v - sqrt(v^2 + 5e-04))/2
+ sum (f * f)
+ }
> 
> p0 <- rexp(50)
> system.time(ans.spg <- spg(par=p0, fn=chen.f, lower=0))[1]
iter:  0  f-value:  31.160868304  pgrad:  1735.79084823 
iter:  10  f-value:  0.0003302739274  pgrad:  0.00619920677888 
iter:  20  f-value:  6.04773591035e-06  pgrad:  1.43825105414e-05 
user.self 
     0.03 
>  
> z <- sum(ans.spg$par)
> good   <-   61.9720512703
> print(z, digits=16)
[1] 61.97205126995098
> if(any(abs(good - z) > 1e-7)) stop("BB test chen.f a FAILED")
>  
> 
> proc.time()
   user  system elapsed 
   0.17    0.04    0.20