Blog Entry Tuesday, June 18, 2024 (c) James Pate Williams, Jr. FreeLIP Computation of Euler Numbers and Tangent Numbers

FreeLIP is a free large integer package solely created by Professor Emeritus Arjen K. Lenstra of the Number Field Sieve fame. He developed FreeLIP while he was an employee of AT&T – Lucent in the late 1980s. His copyright notice in the header file, lip.h, states copyright from 1989 to 1997. I have been using this excellent number theoretical package since the late 1990s. See the paper by Donald E. Knuth and Thomas J. Buckholtz for the formula for Tangent Numbers. I can’t remember where I got the Euler Numbers recurrence relation. I wrote a C# application in 2015 for computing Euler Numbers. The code below is in the vanilla C computer language. Excellent resources for the Euler and tangent numbers also known as zag numbers are:

https://oeis.org/A122045

https://oeis.org/A000182

Blog Entry Sunday, June 16, 2024 (c) James Pate Williams, Jr. Chapter 4 Matrices and Systems of Linear Equations from a Textbook by S. D. Conte and Carl de Boor

Blog Entry Friday, June 14, 2024 (c) James Pate Williams, Jr.

For the last week or so I have been working my way through Chapter 3 The Solution of Nonlinear Equations found in the textbook “Numerical Analysis: An Algorithmic Approach” by S. D. Conte and Carl de Boor. I also used some C source code from “A Numerical Library in C for Scientists and Engineers” by H. T. Lau, PhD. I implemented twenty examples and exercises from the previously mentioned chapter.

Blog Entry June 5-7, 2024, (c) James Pate Williams, Jr. All Applicable Rights Reserved Chapter 7 Example and Some Exercises from “Numerical Analysis: An Algorithmic Approach (c) 1980 by S. D. Conte and Carl de Boor (Numerical Differentiation and Numerical Integration)

Blog Entry June 3-4, 2024, (c) James Pate Wiliams, Jr., Solution of Tridiagonal Matrix Problems

The first solution is from the textbook, Elementary Numerical Analysis: An Algorithmic Approach (c) 1980 by S. D. Conte and Carl de Boor. I translated the FORTRAN code to vanilla C using Visual Studio 2019 Community Version. The second solution is from Boundary Value Problems Second Edition (c) 1979 by David L. Powers. It solves a simple second order linear ordinary differential equation using the finite element difference equation method.

Blog Entry for Early Morning Friday, May 31, 2024, Solutions of a Second Order Self-Adjoint Ordinary Differential Equation by Three Methods