R Under development (unstable) (2026-02-18 r89435 ucrt) -- "Unsuffered Consequences"
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> 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="Mersenne-Twister", normal.kind="Inversion", seed=1234)
> old.seed <- setRNG(test.rng)
> 
> troesch <- function(x) {
+   n <- length(x)
+   tnm1 <- 2:(n-1)
+   f <- rep(NA, n)
+     h <- 1 / (n+1)
+     h2 <- 10 * h^2
+     f[1] <- 2 * x[1] + h2 * sinh(10 * x[1]) - x[2] 
+     f[tnm1] <- 2 * x[tnm1] + h2 * sinh(10 * x[tnm1]) - x[tnm1-1] - x[tnm1+1]    
+ 
+     f[n] <- 2 * x[n] + h2 * sinh(10* x[n]) - x[n-1] - 1
+   f
+   }
>   
> 
> p0 <- matrix(runif(50), 5, 10)  # 5 starting values, each of length 10
> #ans <- BBsolve(par=p0, fn=troesch)
> ans <- multiStart(par=p0, fn=troesch)
Parameter set :  1 ... 
  Successful convergence.
Parameter set :  2 ... 
  Successful convergence.
Parameter set :  3 ... 
  Successful convergence.
Parameter set :  4 ... 
  Successful convergence.
Parameter set :  5 ... 
  Successful convergence.
> ans$par
             [,1]         [,2]         [,3]        [,4]        [,5]        [,6]
[1,] 7.334505e-05 0.0002072649 0.0005125418 0.001241411 0.002996175 0.007227533
[2,] 7.333860e-05 0.0002072840 0.0005125398 0.001241385 0.002996190 0.007227555
[3,] 7.330212e-05 0.0002072497 0.0005125399 0.001241410 0.002996208 0.007227538
[4,] 7.335155e-05 0.0002072763 0.0005125371 0.001241404 0.002996218 0.007227563
[5,] 7.332926e-05 0.0002072850 0.0005125493 0.001241387 0.002996177 0.007227535
           [,7]       [,8]      [,9]     [,10]
[1,] 0.01743732 0.04213119 0.1026836 0.2638176
[2,] 0.01743731 0.04213120 0.1026835 0.2638176
[3,] 0.01743725 0.04213114 0.1026835 0.2638176
[4,] 0.01743730 0.04213120 0.1026836 0.2638175
[5,] 0.01743730 0.04213120 0.1026835 0.2638176
> ans$info
NULL
> 
> # ans$convergence
>  
> z <- sum(ans$par)
> good   <-    2.191639378551349
> #on Windows 
> #on Linux64 
> #on Linux32  2.191639378551349
> print(z, digits=16)
[1] 2.191639378551339
> if(any(abs(good - z) > 5e-9)) stop("BB test BBsolve Troesch FAILED")
> 
> proc.time()
   user  system elapsed 
   0.18    0.04    0.21