Author: jamespatewilliamsjr
Comparison of Aitkin Extrapolation and Newton’s Method to Compute Square Roots by James Pate Williams, Jr.




Comparison of Linear Systems Applications in C# and C++ by James Pate Williams, Jr.
Back in 2017 I created a C# application that implemented the direct methods: Cholesky decomposition, Gaussian elimination with partial pivoting, LU decomposition, and simple Gaussian elimination. The classical iterative methods Gauss-Seidel, Jacobi, Successive Overrelaxation, and gradient descent were also implemented along with the modern iterative methods: conjugate gradient descent and Modified Richardson’s method. Recently I translated the C# code to C++. I used the following test matrices: Cauchy, Lehmer, Pascal, and other. Below are some results. As is apparent the C++ runtimes are faster than the C# execution times.
Richardson Method Translated from C Source Code to C# by James Pate Williams, Jr.


The Richardson Method is called before eliminating the system of linear equations.
Added elimination results from a vanilla C program and a C# application.


These results are not in total agreement with H. T. Lau’s results.
Finite Difference Method for Solving Second Order Ordinary Differential Equations by James Pate Williams, Jr.
My reference is Numerical Analysis: An Algorithmic Approach 3rd Edition by S. D. Conte and Carl de Boor Chapter 9.1.




My 1988 Commodore Amiga 2000 Is Still Functioning by James Pate Williams, Jr.
On Friday September 8, 2023, I setup my thirty-five-year-old personal computer which is a Commodore Amiga 2000. My father bought the computer for me on Saturday, April 30, 1988. It still works although the Commodore 1084 RGB color display has a non-functional power button. My remedy for the problem was to Scotch tape the power button in the “On” position. I have an Amiga BASIC by Microsoft manual and software, a Modula-2 compiler, Motorola MC68000 macro-assembly language software, and a Pecan UCSD Pascal compiler. The Amiga was the first multimedia personal computer. In May 1988 I created two Amiga BASIC programs: a keyboard emulator and a primitive computer-generated music program that used three types of noise namely Brownian, fractal, and white noise. I used the computer extensively in the years 1988 to 1994. In December 1994 my mother and older sister purchased a mom-and-pop store Microsoft-Intel personal computer.

Curve Fitting Using Orthogonal Polynomials in C# by James Pate Williams, Jr.
The curve in this best fit example is the function y(x) = exp(x).




Derivation of de Broglie’s Wave-Particle Duality Principle of Quantum Mechanics and Macroscopic Exercise by James Pate Williams, Jr.
Euler’s Method and Runge-Kutta 4 Algorithm for Numerically Solving an Ordinary Differential Equation by James Pate Williams, Jr.
I added the Runge-Kutta 4 algorithm found in Numerical Analysis: An Algorithmic Approach Third Edition by S. D. Conte and Carl de Boor. I also added a multistep method, the Adams-Bashforth Method.




Estimated Babe Ruth 1921 Homerun Parameters by James Pate Williams, Jr.
“Babe Ruth is generally considered the owner of the record for the longest home run in MLB history with a 575-foot bomb launched at Navin Field in Detroit in 1921.” – https://www.msn.com/en-us/sports/mlb/what-is-the-longest-home-run-in-mlb-history/ar-AA1dGwlZ




As you can see, I estimated the pitch velocity at 90 miles per hour and Babe Ruth’s (Sultan of Swing) at 90 miles per hour also. My analytic calculations yield a range of the baseball’s trajectory as about 576 feet.