Hello,
And sorry for the late reply.
You see, my problem is that it is not known a priori whether I have one
or two zeros of my function in the interval where I am considering it;
on top of that, does BBsolve allow me to select an interval of variation
of x?
Many thanks
Lorenzo
On 09/26/2010 04:31 AM, Jorge Ivan Velez wrote:
Dear Lorenzo,
You could try the BB package:
# function we need the roots for
fn1 <- function(x, a) - x^2 + x + a
# plot
curve(fn1(x, a = 5), -4, 4)
abline(h=0, col = 2)
# searching the roots in (-4, 4)
# install.packages('BB')
require(BB)
BBsolve(par = c(-1, 1), fn = fn1, a = 5)
values <- BBsolve(par = c(-1, 1), fn = fn1, a = 5)$par
values
# adding the roots to the plot
points(values, c(0, 0), pch = 8, cex = 1.1, col = 4)
HTH,
Jorge
On Sat, Sep 25, 2010 at 8:24 PM, Lorenzo Isella <> wrote:
Dear All,
I need to find the (possible multiple) zeros of a function f within
an interval. I gave uniroot a try, but it just returns one zero and
I need to provide it with an interval [a,b] such that f(a)f(b)<0.
Is there any function to find the multiple zeros of f in (a,b)
without constraints on the sign of f(a) and f(b)?
Many thanks
Lorenzo
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