Try this:
func <- function(x) {} body(func) <- D(quote(x^2-1), "x") uniroot(func, interval=c(-0.1,1.1), tol=1e-6) On 4/13/07, Patrick Wang <[EMAIL PROTECTED]> wrote: > Hi, All > > Assume I have function x^2-1, I tried to find the root of its derivative > 2*x = 0. > > I run the command below but it return 1, root of the original function. > Does anyone know how to get the root of the derived function? > > Thanks > pat > ======================================== > func = deriv(parse(text="x^2-1"), "x", func=TRUE) > uniroot(func, interval=(-0.1,1.1), tol=1e-6) > ======================== > $root > [1] 1 > > $f.root > [1] -1.709702e-07 > attr(,"gradient") > x > [1,] 2 > > ______________________________________________ > [EMAIL PROTECTED] mailing list > https://stat.ethz.ch/mailman/listinfo/r-help > PLEASE do read the posting guide http://www.R-project.org/posting-guide.html > and provide commented, minimal, self-contained, reproducible code. > ______________________________________________ [EMAIL PROTECTED] mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.