Chapter 9: Numerical Differentiation - Purdue University
www.cs.purdue.edu › homes › enhExamples: D[Exp[x],x] Ex D[x^3, x] 3 x2 D[x^3, {x, 2}] {second derivative 6x D[x^2 y, x] {partial derivative 2 x y D[ f(x), x] - evaluates first derivative off(x) with respect to x. (Can also be applied to f(x1, x2, . . .).) D[ f(x), {x, n} ] - evaluates nth derivative off(x) with respect to x.
5 Numerical Differentiation
www2.math.umd.edu › lecture-notes › differentiation-chapexample, it is easy to verify that the following is a second-order approximation of the second derivative f00(x) ≈ f(x+h)−2f(x)+f(x−h) h2. (5.6) To verify the consistency and the order of approximation of (5.6) we expand f(x±h) = f(x)±hf0(x)+ h2 2 f00(x)± h3 6 f000(x)+ h4 24 f(4)(ξ ±). Here, ξ − ∈ (x−h,x) and ξ + ∈ (x,x+h). Hence
Numerical Differentiations Solved examples
www.slideshare.net › Developedia › numericalJan 10, 2016 · Numerical Differentiations Solved examples 1. Numerical differentiation 31.3 Introduction In this Section we will look at ways in which derivatives of a function may be approximated numerically. ' $ % Prerequisites Before starting this Section you should . . . ① review previous material concerning differentiation Learning Outcomes After completing this Section you should be able to . . . obtain numerical approximations to the first and second derivatives of certain functions
NUMERICAL DIFFERENTIATION
homepage.divms.uiowa.edu › ~atkinson › ftpExample. Calculate Dc(2) h (x1) for f(x) = cos(x) at x1 = 1 6 ˇ. To show the e ect of rounding errors, the values fb iare obtained by rounding f(xi) to six signif-icant digits; and the errors satisfy j ij 5:0 10 7 = ; i= 0;1;2 Other than these rounding errors, the formula Dc(2) h f(x1) is calculated exactly. In this example, the bound (19) becomes f 00(x1) Dc (2)
Numerical Differentiation - UC Santa Barbara
www.mrl.ucsb.eduA Chebyshev Example Let’s use both methods to differentiate the analytic function y(x) = exp(x)*sin(5x) over [-1,1] using N=10 and N=20 points Now the case of Chebyshev differentiation: see ChebDExample.m The error is O(10-2) at N=10 and O(10-10) at N=20! This is a stunning example of spectral accuracy: