R Under development (unstable) (2023-12-09 r85665 ucrt) -- "Unsuffered Consequences"
Copyright (C) 2023 The R Foundation for Statistical Computing
Platform: x86_64-w64-mingw32/x64

R is free software and comes with ABSOLUTELY NO WARRANTY.
You are welcome to redistribute it under certain conditions.
Type 'license()' or 'licence()' for distribution details.

R is a collaborative project with many contributors.
Type 'contributors()' for more information and
'citation()' on how to cite R or R packages in publications.

Type 'demo()' for some demos, 'help()' for on-line help, or
'help.start()' for an HTML browser interface to help.
Type 'q()' to quit R.

> suppressPackageStartupMessages(library(float))
> set.seed(1234)
> 
> tol = 1e-6
> 
> x = crossprod(matrix(stats::rnorm(30), 10))
> xs = fl(x)
> y = 1:3
> ys = fl(y)
> z = cbind(y, rev(y))
> zs = fl(z)
> 
> 
> test = dbl(backsolve(xs, ys, upper.tri=FALSE))
> truth = backsolve(x, y, upper.tri=FALSE)
> stopifnot(all.equal(test, truth, tol=tol))
> 
> test = dbl(backsolve(xs, ys))
> truth = backsolve(x, y)
> stopifnot(all.equal(test, truth, tol=tol))
> 
> test = dbl(backsolve(xs, ys, k=2))
> truth = backsolve(x, y, k=2)
> stopifnot(all.equal(test, truth, tol=tol))
> 
> test = dbl(backsolve(xs, zs))
> truth = backsolve(x, z)
> stopifnot(all.equal(test, truth, tol=tol))
> 
> test = dbl(backsolve(xs, zs, k=2))
> truth = backsolve(x, z, k=2)
> stopifnot(all.equal(test, truth, tol=tol))
> 
> proc.time()
   user  system elapsed 
   0.31    0.09    0.34