L-system trees form realistic models of natural patterns Origins 'Weeds', generated using an L-system in 3D. As a biologist, Lindenmayer worked with yeast and filamentous fungi and studied the growth patterns of various types of algae, such as the blue/green bacteria Anabaena catenula. Originally the L-systems were devised to provide a formal description of the development of such simple multicellular organisms, and to illustrate the neighbourhood relationships between plant cells. L-system structure The recursive nature of the L-system rules leads to self-similarity and thereby, fractal-like forms are easy to describe with an L-system. L-system grammars are very similar to the semi-Thue grammar (see Chomsky hierarchy). G = (V, ω, P), where The rules of the L-system grammar are applied iteratively starting from the initial state. An L-system is context-free if each production rule refers only to an individual symbol and not to its neighbours. Examples of L-systems start : A
Trace theoryIn mathematics and computer science, trace theory aims to provide a concrete mathematical underpinning for the study of concurrent computation and process calculi. The underpinning is provided by an algebraic definition of the free partially commutative monoid or trace monoid, or equivalently, the history monoid, which provides a concrete algebraic foundation, analogous to the way that the free monoid provides the underpining for formal languages. The power of trace theory stems from the fact that the algebra of dependency graphs (such as Petri nets) is isomorphic to that of trace monoids, and thus, one can apply both algebraic formal language tools, as well as tools from graph theory. V.
L-Systems ExplorerDownload here (94K) - Note: you will need MFC42.DLL to run this. LSE, or L-Systems Explorer, is a program that allows you to design or view Lindenmeyer Systems (L-Systems). L-Systems are simple string-based commands (much like Turtle graphics) that allow various shapes to be drawn. The interest in Artificial Life is that they can create very life-like tree structures from simple commands. LSE was designed to replace LSD, since the dialog-based nature of the program limited what could be done with it. This more advanced program was inspired by the drawings and chapter on L-Systems in The Computational Beauty of Nature. LSE has the following improvements: Allows for up to 26 different rules Loading and saving of rules Zooming, panning and depth adjustment. Note this is the same L-System, with the depths set at 0-4 from left to right. L-System Commands L-Systems Explorer allows you to assign up to 26 recursive rules. Using LSE Version 1.1 A few bugs fixed, and gradient support added.
Lehrstuhl Grafische Systeme - Projekte - Virtuelle PflanzenRelationale Wachstumsgrammatiken als Basis für ein mehrskaliges metabolisches Strukturmodell der Gerste: Neue Techniken der Informatik für Functional-Structural Plant Models (FSPM) Im Rahmen des Vorläuferprojekts wurde die formale Modellspezifikations-Sprache der Relationalen Wachstumsgrammatiken (Relational Growth Grammars, RGG) entwickelt, mit der interaktiven Software GroIMP (Growth Grammar Related Interactive Modelling Platform) operabel gemacht und an ersten Beispielen demonstriert. Da Formalismus und Software zunächst schrittweise ausgebaut und getestet werden mussten, waren diese Beispiele bisher auf sehr ausschnitthafte Modelle beschränkt. Kooperationspartner: Institut für Pflanzengenetik und Kulturpflanzenforschung (IPK) Gatersleben, Dr. Abschlussbericht andere Projekte am Lehrstuhl zurück zur Homepage des Lehrstuhls
RewritingIn mathematics, computer science, and logic, rewriting covers a wide range of (potentially non-deterministic) methods of replacing subterms of a formula with other terms. What is considered are rewriting systems (also known as rewrite systems or reduction systems). In their most basic form, they consist of a set of objects, plus relations on how to transform those objects. Rewriting can be non-deterministic. One rule to rewrite a term could be applied in many different ways to that term, or more than one rule could be applicable. Rewriting systems then do not provide an algorithm for changing one term to another, but a set of possible rule applications. Intuitive examples Logic In logic, the procedure for obtaining the conjunctive normal form (CNF) of a formula can be conveniently written as a rewriting system. (double negative elimination) (De Morgan's laws) (Distributivity) where the symbol ( Linguistics Abstract rewriting systems Example 1. , and y is irreducible. .
Newsroom - Software allows interactive tabletop displays on WebResearchers have developed a new type of software that enables people to use large visual displays and touch screens interactively over the Internet for business and homeland security applications. Here, users at Purdue and the University of Manitoba in Canada interact as if they were in the same room using the same display. (School of Electrical and Computer Engineering, Purdue University) Download image WEST LAFAYETTE, Ind. - Researchers have developed a new type of software that enables people to use large visual displays and touch screens interactively over the Internet for business and homeland security applications. Tabletop touch-operated displays are becoming popular with professionals in various fields, said Niklas Elmqvist, an assistant professor of electrical and computer engineering at Purdue University. "These displays are like large iPhones, and because they are large they invite collaboration," he said. Writer: Emil Venere, 765-494-4709, email@example.com
powerPlant | Free Graphics software downloadsCurryingThis article is about the mathematical technique. For the cooking process of this name, see Curry. For the leather finishing process, see Currier. Motivation Currying is similar to the process of calculating a function of multiple variables for some given values on paper. For example, given the function To evaluate , first replace with Since the result is a function of , this new function can be defined as Next, replace the argument with , producing On paper, using classical notation, this is usually done all in one step. If we let f be a function then the function h where is a curried version of . is the curried equivalent of the example above. Definition Given a function of type , currying it makes a function . takes an argument of type and returns a function of type . The → operator is often considered right-associative, so the curried function type is often written as . is equivalent to Mathematical view In a set-theoretic paradigm, currying is the natural correspondence between the set to
Poetry on the Road 2010The metaphoric theme of this years Poetry on the Road visual is a mad origami master. Every poem is represented as a data sculpture made from virtual paper. So this year, we don't have a single key visual but a sequence of individual graphics that represent a single poem. This is also reflected on the design level - a number of poster variations were produced for the festival. The concept in a nutshell: a long paper strip that is folded in an extremely complex manner. Every ridge represents a word. Complex forms - and a long and complex process! Like in the last few years, the visuals for Poetry on the Road were developed with Processing.