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Author Topic: Paper about How cities grow as living organisms  (Read 1530 times)

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Offline vilvoh

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Paper about How cities grow as living organisms
« on: November 21, 2010, 11:00:35 PM »
I've found this interesting paper for the development team and for the rest of Simutrans community too, that talks about a geometrical approach of mathematics and morphogenesis of the city. In other words, algorithms and strategies to simulate city growing. I think it's very interesting as I've noticed that many people ask for this issue and as far as I know, the current algorithm is quite simple, thus perhaps the development team might get some ideas from it.

This is the abstract of the paper:
Quote
Cities can be compared to living organisms. They are out of equilibrium, opened systems that never stop developing and sometimes die. The city's growth is guided by needs in local distribution and in communication among its parts. The local geography can be compared to a shell constraining its development. In brief, a city's current layout is a step in a running morphogenesis process. Thus cities display a huge diversity of shapes and none of traditional models from random graphs, complex networks theory or stochastic geometry takes into account geometrical, functional and dynamical aspects of a city in the same framework. We present here a global mathematical model dedicated to cities that permits describing, manipulating and explaining cities' overall shape and layout of their street systems. This streets-based framework includes an algebraic formalism, a static analysis of cities' main features (topology of first and second order, anisotropy, streets scaling) and a dynamical model which from simple general rules can reproduce a large diversity of cities.

A sample of a city growing acording to the points exposed in the paper



Link: http://arxiv.org/abs/1010.1762

Offline sdog

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Re: Paper about How cities grow as living organisms
« Reply #1 on: November 21, 2010, 11:16:30 PM »
quite an interesting article!

Offline prissi

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Re: Paper about How cities grow as living organisms
« Reply #2 on: November 22, 2010, 09:02:31 AM »
Imho cities grow quite different from the diagram shown there. Usually they start with a dense mesh at the centers and then have more generous roads on the outside.

From a practical point of view this would be rather interesting for the former Stra├če & Schiene, since there a vector based town growth modell was used.

Offline sdog

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Re: Paper about How cities grow as living organisms
« Reply #3 on: November 22, 2010, 05:06:00 PM »
prissi, i can't follow you here. the simulated cities in the paper show the behaviour you described. For example in figures 12 and 13.

Offline prissi

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Re: Paper about How cities grow as living organisms
« Reply #4 on: November 22, 2010, 09:02:05 PM »
The first part of analysis is "only" an interesting description of the data using different metrics. However, the simulation of city growth (fig 11) clearly show that the simulations start with few streets and then grow a denser network at the center. (Also the text stated, taht the growth started from branching two main roads. But as topology is not my main subject, I might have gotten it wrong.)

Offline sdog

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Re: Paper about How cities grow as living organisms
« Reply #5 on: November 22, 2010, 09:38:13 PM »
thanks for the explanation prissi, now i see what you meant.