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MANE 3351

Lecture 9, September 20

Classroom Management

Agenda

  • Example problem from Wednesday
  • Lecture
  • Lab today!

Resources

Handouts


Calendar

Lecture Date Content
1 August 23 Welcome to Class, Syllabus
2 August 25 Error Analysis
3 August 30 Introduction to Jupyter Notebook
4 September 1 Markdown
5 September 6 Labor Day Holiday
6 September 8 Taylor Polynomials, Homework 1
7 September 13 Roots of Equations, Bisection Method
8 September 15 Bisection Error Analysis
9 September 20 False Position Algorithm

Assignments

  • Homework 2 (assigned 9/15/2021, due 9/23/2021)

False Position

  • Attempts to converge faster than bisection method by using functional information
  • Referred to as the secant method in textbook
  • The new root is found by
\[ x_r=x_u-\frac{f(x_u)(x_l-x_u)}{f(x_l)-f(x_u)} \]

  • Figure 5.12 (Chapra and Canale(2015)[^1] illustrates the false position method False Position Method

False Position Code

The pseudocode, shown below was taken from [^2]

False Position Pseudocode


Jupyter Notebook Demonstration


False Position Error Analysis

  • Much harder to analyze than bisection method
  • Convergence to root depends on shape of \(f(x)\)
  • At times, false position may converge slowly!, Example from textbook[^3], shown below

False Position troublesome function


Loops in Python

  • Python only supports two types of loops: for and while
  • Pseudocode used do/while loop

[1]: Chapra, S. and Canale, R. (2015), Numerical Methods for Engineering, 7th edition

[2]: Source: https://www.codesansar.com/numerical-methods/regula-falsi-or-false-position-method-pseudocode.htm

[3]: Brin, L., (2020), Tea Time Numerical Analysis: Experiences in Mathematics, 3rd edition