multrfind: multrfind: Find a single root of a function of one variable...
In rootoned: Roots of one-dimensional functions in R-only code

Description Usage Arguments Details Value References See Also Examples

Find a single root of a function of one variable within a specified interval. Brent's method.

1	multrfind(fn, gr=NULL, ri, ftrace=FALSE, meths="uniroot",...)

`fn`	A real function of a single variable.
`gr`	A real function of a single variable to evaluate the gradient of `fn`.
`ri`	A vector of two real numbers defining the ends of the interval in which to search.
`ftrace`	TRUE if the progress of the methods is to be displayed
`meths`	A vector of character (quoted) names of methods to apply to find real roots of `fn`.
`...`	Dot arguments – extra information that is needed to compute the function and gradient.

This routine calls the rootfinder wrapper rootwrap for each of the named solvers.

The output is a data frame consisting of one row for each of the methods. The columns of the data frame are "root", "froot", "rtol", "iter", "fncount", and "method".

Nash, John C. (1979) Compact numerical methods: linear algebra and function minimisation. Bristol UK: Adam Hilger.

optimize

# Dekker example
require(rootoned)
phi <- 6
dek <- function(x, phi=6){ 1/(x-3) - phi }
mymeth <- c("uniroot", "root1d", "zeroin")
# r1 <- multrfind(dek, ri=c(3.0000001, 6), meths=mymeth, ftrace=TRUE, phi = 6)
r1 <- multrfind(dek, ri=c(3.0000001, 6), meths=mymeth, ftrace=TRUE)
r1