Java applet

Calligraphy is quite popular. I wrote the original 1997 Java applet as a throwaway programming example - but people kept using it. So I turned it into a real product. Latest version features textured and tinted papers, transparent inks, zoom, print options, Undo support, marker as well as chisel nib, etc.

Calligraphy is now available in Slovene! Translation by Milan Ozimek.

ArchaeoSim explores social and environmental tradeoffs in ancient farming civilizations in ancient Subir (northern Mesopotamia). Includes detailed paleoclimate data and completed archaeological survey data. Used in teaching the Yale course Human Creation and Destruction of Environments.

DaisyBall is my custom 3D variation on Lovelock's classic DaisyWorld, with multiple sites around a sphere. Each site is represented by a daisy. Different lattitudes receive different solar input. Daisy color shows the dominant daisy species at each site.

DaisyWorld is the classic model in 2D, demonstrating homeostasis via ecosystem feedback loops (daisy albedo). There is no spatial structure. The daisies indicate percent population at a single site.

Used in teaching "Intro to the Earth System" at UCLA, among other non-Yale courses.

Peter Schoch wrote a DaisyWorld Lab for teaching his community college Physics students (Thermodynamics, and Blackbody radiators). Thank you for sharing, Peter!

IFS with Memory applies selected sequences of affine transforms, subdividing an ancestral square, to generate fractal pictures. Sequence selection is in 2D or 3D.

Random IFS with Memory runs iterated function systems on an initial point. The user can set allowed/disallowed sequences of transforms in 1-step or 2-step memory.

Box Dimension explores the idea of fractal dimension by counting boxes along geographical edges. Latest version allows user to supply his own pictures.

Mandelbrot-Julia Sets explores the famous Mandelbrot Set and its associated Julia Sets with paired plots. Each point of a Mandelbrot set generates a Julia set. Includes Julia orbits, several color schemes, and alternate functions besides the usual z2.

I also have a simpler Flash version. This was written as an ActionScript 3 performance test.

Predator/Prey with Functional Response is Predator/Prey plus a first scenario to explore Types I, II, and III functional response, the function that relates predator consumption rate to prey abundance. This is the variant of Predator/Prey assigned in class at Yale.

FracStats does R/S analysis and comparison to a normal distribution, on a time series, with or without difference processing on the input data. Also does multifractal analysis (f(alpha) curves) on time series or planar data, using either the method of moments or histogram method. Several data sets are supplied, but the main use is to paste in your own data to explore.