spuRs (version 1.0.5)

fixedpoint: A function of the fixed point algorithm.

Description

Applies the fixed point algorithm to find x such that ftn(x) == x.

Usage

fixedpoint(ftn, x0, tol = 1e-09, max.iter = 100)

Arguments

ftn

the function.

x0

is the initial guess at the fixed point.

tol

distance of successive iterations at which algorithm terminates.

max.iter

maximum number of iterations.

Value

• Returns the value of x at which ftn(x) == x. If the function fails to converge within max.iter iterations, returns NULL.

Details

We assume that ftn is a function of a single variable.

References

Jones, O.D., R. Maillardet, and A.P. Robinson. 2009. An Introduction to Scientific Programming and Simulation, Using R. Chapman And Hall/CRC.

See Also

newtonraphson, bisection

Examples

ftn1 <- function(x) return(exp(exp(-x)))
fixedpoint(ftn1, 2, tol = 1e-6)