This help topic is for R version 0.60. For the current version of R, try https://stat.ethz.ch/R-manual/R-patched/library/base/html/uniroot.html
uniroot {base}R Documentation

One Dimensional Root Finding

Description

The function optimize searches the interval from lower to upper for a zero of the function f with respect to its first argument.

The function uses Fortran code (from Netlib) based on algorithms given in the reference below.

Usage

uniroot(f, interval, lower = min(interval), upper = max(interval),
        tol = .Machine$double.eps^0.25, ...)

Arguments

f

the function for which the root is sought.

interval

a vector containing the end-points of the interval to be searched for the root.

lower

the lower end point of the interval to be searched.

upper

the upper end point of the interval to be searched.

tol

the desired accuracy.

...

additional arguments to f.

Value

A list with components root and f.root which give the location of the root and the value of the function evaluated at that point.

References

Brent, R. (1973). Algorithms for Minimization without Derivatives. Englewood Cliffs, NJ: Prentice-Hall.

See Also

polyroot for all complex roots of a polynomial; optimize, nlm.

Examples

f <- function (x,a) x - a
xmin <- uniroot(f, c(0, 1), tol = 0.0001, a = 1/3)
xmin

[Package base version 0.60 ]