Not sure about Agent-based models, but Benenson and Torrens have a formal definition for Geographic Automata Systems (GAS). More on that is available in their book on Geosimulation <http://www.geosimulationbook.com/>
--snip-- Formally, a Geographic Automata System (GAS), G, may be defined as consisting of seven components: G ~ (K; S, TS; L, ML; R, NR) Here K denotes a set of types of automata featured in the GAS and three pairs of symbols denote the rest of the components noted above, each representing a specific property and the rules that determine its dynamics. The first pair denotes a set of states S, associated with the GAS, G (consisting of subsets of states Sk of automata of each type kÎK), and a set of state transition rules TS, used to determine how automata states should change over time. The second pair represents location information. L denotes the geo-referencing conventions that dictate the location of automata in the system and ML denotes the movement rules for automata, governing changes in their location. According to general definition (1) – (2), state transitions and changes in location for geographic automata depend on automata themselves and on input (I), given by the states of neighbors. The third pair in (4) specifies this condition. R represents neighbors of the automata and NR represents the neighborhood transition rules that govern how automata relate to the other automata in their vicinity. . --snip-- More reading: Benenson, I. & *Torrens, P.M.* (2004) *Geosimulation: Automata-Based Models of Urban Phenomena <http://www.geosimulationbook.com/>*. Chichester: John Wiley & Sons. Benenson, I. & *Torrens, P.M. *(2004) "Geosimulation: object-based modeling of urban phenomena<http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6V9K-482YTP2-2&_user=10&_coverDate=03%2F31%2F2004&_rdoc=1&_fmt=summary&_orig=browse&_sort=d&view=c&_acct=C000050221&_version=1&_urlVersion=0&_userid=10&md5=af4a11dff3aadf9aadac26a912266168>". *Computers, Environment and Urban Systems* 28 (1/2): 1-8. On 5/9/07, Owen Densmore <[EMAIL PROTECTED]> wrote:
Is there a formal definition of Agent Based Model? By "formal definition" I mean something like there is for a Finite State Automata: A Finite State Automata is definded as a 5-tuple (Q, Σ, δ, q0, F) where 1 - Q is a finite set called the states. 2 - Σ is a finite set called the alphabet 3 - δ: Q X Σ -> Q is the transition function 4 - q0 ∈ Q is the start state, and 5 - F ⊆ Q is the set of accept states (Note: the above uses Unicode so if your display is odd, its trying to show symbols for Sigma, Delta and so on) If not, we ought to build one, right? Wikipedia discusses both CAs and ABMs: http://en.wikipedia.org/wiki/Cellular_automata http://en.wikipedia.org/wiki/Agent_based_model .. as well as FSA: http://en.wikipedia.org/wiki/Finite_state_automata Note that only the latter has a formal definition in the article. -- Owen ============================================================ FRIAM Applied Complexity Group listserv Meets Fridays 9a-11:30 at cafe at St. John's College lectures, archives, unsubscribe, maps at http://www.friam.org
Sudhira -- ---------------------------------------------------------------------------------------------------------------- Research Scholar, Ph.D., Department of Management Studies and Centre for Sustainable Technologies, Indian Institute of Science, Bangalore - 560 012, Karnataka State, INDIA ----------------------------------------------------------------------------------------------------------------
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