An R implementation of the binary search of the zero of a
continous strictly monotone real function.
Usage
binarysearch(lb, ub, fun, tol = 1e-08)
Arguments
- lb
A single numeric value, the lower bound of the interval to seek in the zero point.
- ub
A single numeric value, the upper bound of the interval to seek in the zero point.
- fun
A continuous monotone real function defined on the interval
[lb, ub] such that fun(lb)*fun(ub) < 0.
- tol
The precision of the approximation of the zero point to be attained.
Default value is 1e-8.
Value
A list with three components :
sol, the approximation of the zero point for function fun ;
prec, the precision of the approximation, of the form (ub - lb)/2^(iter+1) ;
iter, the number of iterations of the binary search while processing the approximation.
Examples
tmpfun <- function(x) return(sqrt(x)-2)
tmpub <- 9
tmplb <- 1
binarysearch(lb = tmplb, ub = tmpub, fun = tmpfun)
#> $sol
#> [1] 4
#>
#> $prec
#> [1] 7.450581e-09
#>
#> $iter
#> [1] 29
#>