Java and JavaScript

Bluffton University > Mathematics > Darryl Nester > Java[Script] Projects

Below are the Java and JavaScript projects I have produced, organized by category. Most of these are JavaScript, so they should be compatible with most browsers. The Java pages (marked with ) may be problematic, because of security restrictions with unsigned Java applets. (I am reluctant to shell out the money to purchase a "certificate" so that I can sign my applets.) If you want to run them, make sure you have the latest version of Java installed (visit javatester.org to see your version), and investigate how to adjust the Java security settings on your computer. If you use Firefox, you might need to reset the "Zoom" level ("View: Zoom: Reset") in order for these applets to display correctly.

Calculus

Slope and direction fields—display slope fields and solution curves for first-order ODEs, and direction fields for first-order systems.
Derivative practice—this page generates random functions, and allows you to try to find the derivative.
Integral practice—(beta version—still needs work) find the antiderivative of randomly-generated functions.
Compartmental Analysis Modeling—create and run simple compartmental analysis models (like a very limited version of VenSim or STELLA).
Riemann sums—(Dec. 2013) illustrates rectangular approximations to definite integrals.
Exploring orthogonal trajectories—now with an improved interface. I think this now runs correctly on all machines with up-to-date Java.
Reflecting Walls for Bouncing Balls—animated orthogonal trajectories for families of projectile-motion paths.

Geometry

Hyperbolic Geometry—(upd. Jan. 2022) construct lines, circles, etc. in hyperbolic geometry (Poincarè halfplane, Poincarè disc, Cayley/Beltrami-Klein)
Projective Geometry—(Dec. 2020—alpha) simple projective geometry demos
Slicing triangles and quadrilaterals—(Nov. 2024) find segments that divide a triangle or quadrilateral in half (by area).

Probability and Statistics

Statistics Playground—(upd. Jan. 2025) Enter or paste data, then view summary statistics and various graphs (histograms, boxplots, scatterplots) to understand distributions and relationships.
Exploring probability distributions—(Jan. 2014—beta) view the mass functions/densities of up to four distributions.
Rook Polynomials—computes the "rook polynomial" for a user-specified chessboard.
Quincunx / Galton Box / Bean Machine—watch marbles fall through a grid of "pins" and pile up at the bottom.
Regression Toy—explore what the "best fit" line looks like, with various definitions of what is "best."
How to Get a Date—a simulation of two (or three) men trying to decide when they should call "Ann" to get a date.
Markov Chain Analysis—explore finite Markov chains

Computer Programming

Recursive "painting"—a (crude) demonstration of the "fill" function found in most paint programs.
Sorting Algorithms demonstration—with "source code" tracing.
Making Mazes—observe the step-by-step process of making mazes (using several different algorithms).

Operations Research

Queueing Theory Simulation (beta)—Monte Carlo simulation of queues.
Linear Programming/Simplex method (beta)—Step-by-step illustrations of the simplex method of solving LP problems.
Excel Simulations Package—functions to aid in constructing Monte Carlo simulations in Excel spreadsheets, including many standard probability distributions, performing multiple iterations, and generating summary statistics and histograms.

Recreational Math

The A-Maze-Ing Puzzle—Can you find the starting point of a randomly generated maze?
KenKen helper—see all the possible ways to fill in the cages in the puzzle KenKen.
End Game SET—(Dec. 2014) determine the missing card at the end of a game of SET.
Pursuit polygon tilings—(Apr. 2016) produce pretty pictures by packing the plane with "pursuit polygons"—inspired by this YouTube video.

Misc. Mathematics Classes

Voting methods demonstrations—illustrates several standard voting methods.
Graph algorithms—(updated Jan. 2014) apply the nearest-neighbor, sorted edges, Kruskal's, Prim's, and Dijkstra's algorithms to a randomly-generated graph.
Reproduction Curves—(Sept. 2014) specify a reproduction curve for a population (logistic or other), and see the effect of iteration on that curve (equilibrium, oscillation, or chaos).
Mathematics of Non-renewable Resources—(March 2016) how long will a non-renewable resource (oil, natural gas, etc.) last?
Number base conversions—illustrates conversions between base 10 and other bases.
Pythagorean triples—produces a sortable list of Pythagorean triples (all, or just primitive).
Grapher—(upd. Oct. 2014) graph up to five functions, four parametric curves, and four polar curves, with optional smoothing and discontinuity detection.
Grapher (improved)—(Nov. 2020) graphs functions, as well as polar, parametric, and implicit relations.
Bezier toy—play with bezier curves (quadratic, cubic, and higher)

Miscellaneous

The "Secret Santa Server"—a Web page to help choose names for a gift exchange (ensuring that no one draws his/her own name, and any other custom restrictions you would like).
Maze Profiler—how does the algorithm used to create a maze affect its appearance?
The Three Sticks puzzle—my first applet (and it shows).
David's science project—this was put together in 2010 to gather data for my son's middle school science fair project (comparing left and right hand dexterity with a computer mouse). We are no longer collecting data, but feel free to give it a try anyway.