R: Taylor expansion (one dimension)

taylor {doBy} | R Documentation

## Taylor expansion (one dimension)

### Description

Returns Taylor polynomial approximating a function fn(x)

### Usage

    taylor(fn, x0, ord = 1)

### Arguments

`fn` | A function of one variable and that variable must be named 'x'.
`x0` | The point in which to to the Taylor expansion.
`ord` | The order of the Taylor expansion.

### Value

function.

### Author(s)

Søren Højsgaard, sorenh@math.aau.dk

### Examples

    fn <- function(x) log(x)
    ord <- 2
    x0 <- 2

    xv  <- seq(.2, 5, .1)
    plot(xv, fn(xv), type="l")
    lines(xv, taylor(fn, x0=x0, ord=ord)(xv), lty=2)
    abline(v=x0)

    fn <- function(x)sin(x)
    ord <- 4
    x0 <- 0
    xv <- seq(-2*pi, 2*pi, 0.1)
    plot(xv, fn(xv), type="l")
    lines(xv, taylor(fn, x0=x0, ord=ord)(xv), lty=2)
    abline(v=x0)

[Package doBy version 4.6.5 Index]