secant: A function to find roots of univariate functions.

Description Usage Arguments Value Author(s) References Examples

Description

Finds the roots of univariate functions by using the Secant method.

Usage

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secant(fun, x0, x1, eps, maxit = 20, silent = FALSE)

Arguments

fun

a function for which the root is searched.

x0

a numeric value to be used to start the algorithm (first initial).

x1

a numeric value to be used to start the algorithm (second initial).

eps

a numeric value to be considered as the tolerance for convergence of the algorithm.

maxit

a numeric value which denotes maximum number of iterations to be consumed.

silent

a logical statement which decides whether the iterations should be printed.

Value

Returns a numeric result.

Author(s)

Ozlem Ilk, Ozgur Asar

References

Ilk, O. (2011). R Yazilimina Giris [Introduction to R Language]. ODTU Yayincilik [METU Press].

Examples

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## Example-1
f1=function(x) x^3+sqrt(x)-1
secant(f1,0.5,0.55,10^-10,silent=FALSE)

## Example-2
f2=function(x) x^3-sinh(x)+4*x^2+6*x+9
# searching for reasonable initials
x0=seq(-10,10,,100)
plot(x0,f2(x0),type="n")
lines(x0,f2(x0))
x0=seq(6,8,,100)
plot(x0,f2(x0),type="n")
lines(x0,f2(x0))
abline(h=0,lty=2)

secant(f2,7,7.2,10^-10,maxit=30,silent=FALSE)

Example output

Iterasyon: 1 , Result= 0.610619
Iterasyon: 2 , Result= 0.6051663
Iterasyon: 3 , Result= 0.6054222
Iterasyon: 4 , Result= 0.6054234
Iterasyon: 5 , Result= 0.6054234
Solution: 0.6054234
[1] 0.6054234
Iterasyon: 1 , Result= 7.106078
Iterasyon: 2 , Result= 7.112647
Iterasyon: 3 , Result= 7.113065
Iterasyon: 4 , Result= 7.113063
Iterasyon: 5 , Result= 7.113063
Solution: 7.113063
[1] 7.113063

OOmisc documentation built on May 1, 2019, 10:17 p.m.

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