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 froth ...\n")
BB test froth ...
> 
> froth <- function(p){
+ # Freudenstein and Roth function (Broyden, Mathematics of Computation 1965, p. 577-593)
+ f <- rep(NA,length(p))
+ f[1] <- -13 + p[1] + (p[2]*(5 - p[2]) - 2) * p[2]
+ f[2] <- -29 + p[1] + (p[2]*(1 + p[2]) - 14) * p[2]
+ sum (f * f)
+ }
> 
> p0 <- rpois(2,10)
> system.time(ans.spg <- spg(par=p0, fn=froth, control=list(M=20, maxit=2500)))[1]
iter:  0  f-value:  90842  pgrad:  99836.0048106 
iter:  10  f-value:  168.571319021  pgrad:  30.4387560845 
iter:  20  f-value:  53.7424011506  pgrad:  2.95705866904 
iter:  30  f-value:  54.695078884  pgrad:  80.9336462737 
iter:  40  f-value:  50.1273929575  pgrad:  1.40112319968 
iter:  50  f-value:  50.8368121528  pgrad:  49.5256877997 
iter:  60  f-value:  49.3250968325  pgrad:  0.773142900812 
iter:  70  f-value:  49.1136353221  pgrad:  0.46335657089 
iter:  80  f-value:  49.0609920845  pgrad:  0.352581110974 
iter:  90  f-value:  49.0506330175  pgrad:  9.94959741263 
iter:  100  f-value:  48.9845020039  pgrad:  0.564741426956 
user.self 
     0.02 
> #ans.spg
> system.time(ans.opt <- optim(par=p0, fn=froth, method="L-BFGS-B"))[1]
user.self 
        0 
> 
> z <- sum(ans.spg$par)
> good   <-   10.51597043896899
> #on Windows 10.51597043896899
> #on Linux64 10.51597043896899
> #on Linux64 10.51597048420193 Ubuntu 10.04
> #on Linux32 10.51597043896899
> print(z, digits=16)
[1] 10.51597048420193
> if(any(abs(good - z) > 1e-7)) stop("BB test froth a FAILED")
>  
> z <- sum(ans.opt$par)
> good    <-  9.00000701456296
> #on Windows 9.00000701456296
> #on Linux64 9.00000701456296
> #on Linux32 9.00000701456296
> print(z, digits=16)
[1] 9.000007014562957
> if(any(abs(good - z) > 1e-12)) stop("BB test froth  b FAILED")
> 
> proc.time()
   user  system elapsed 
   0.21    0.06    0.21