Thanks all for the interesting discussion. Herewith my feedback:
The log-log lines are not very straight, and in some case seem pretty
curved. However the pattern (80/20 partition around the average m) we
illustrated seems universal. With this pattern we do believe power-law
there.
> but this is curved throughout the length - very clearly so - I suspect a
> simple power function which would still be interesting...
>
>
>> One of the problems I had in the Physica A paper was that we do not know
>> what a street is. There are several representations out there, but there
>> is no uniquely accepted concept?
>>
>
> Agreed - an argument for a (comparatively) well defined concept like the
> axial line perhaps? :-)
>
Well, I cannot agree with the point. Through the experiments, we see the
concept of streets based on perceptual grouping is pretty clearly
defined, much better than axial lines. People may argue that the
criteria of good continuity is a bit vague. In fact, we tried different
threshold angles (actually a series from 20 to 90 degrees) for merging
(or grouping) street segments to form individual streets, and found no
big change in the illustrated pattern. One of my students Chengke Liu
has testified three models: axial, stroke, named streets, and found the
latter two are the best.
Cheers.
Bin
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Bin Jiang
Department of Land Surveying and Geo-informatics
The Hong Kong Polytechnic University
Hung Hom, Kowloon, Hong Kong.
Tel: (852) 2766 4335, Fax: (852) 2330 2994
Email: [log in to unmask]
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