On Tue, 9 Jan 2007 17:00:05 -0000, Alain Chiaradia
<[log in to unmask]> wrote:
>Dear Rui
>
>Knowing how well you are aware about the convex space coverage problem,
>you may perhaps entertain us with comments and enlightenments on most
>transport demand models use of region definition, which understood as the
>modifiable area unit problem, sometimes know as the ecological fallacy.
>Mike as published quite a few papers on this while back, it may provide
>you with a much more serious problem to bask on. Another one is perhaps
>to wonder on how transport model define the bound of the model or the
>network encoding, an accepted mess for too long, I agree, what are your
>thoughts about it?
can't make sense out of this -explain
Rui
________________________________________
Dr. Rui Carvalho
http://www.casa.ucl.ac.uk/rui/
Senior Research Fellow
Centre for Advanced Spatial Analysis
University College London
1-19 Torrington Place
Gower Street
London WC1E 6BT, U.K.
>
>
>Alain
>________________________________________
>
>
>-----Original Message-----
>From: Rui Carvalho
>Sent: 05 January 2007 10:58
>To:
>Subject: Re: How to draw Axial map for traffic analysis?
>
>On Fri, 5 Jan 2007 02:54:03 +0000, Chengke LIU <[log in to unmask]>
wrote:
>
>>Dear all,
>>
>>I am a master student, currently working on my final dissertation of
>>applying space syntax to traffic analysis. I need to draw an axial map of
>>whole Hong Kong territory. I know that Axial map of London consisting
>17321
>>lines is successfully done by somebody.
>>
>>According to the statements made by Hillier and Hanson in 1984, in the
>book
>>named "The Social Logic of Space", the processing of making an axial map
>>should begin with the longest straight line, then the second longest,
and
>so
>>on until the all convex spaces are covered and all axial lines should
>>intersect with each other without repetition. How could the creator of
>>London axial map ensure this principle when he drew the map?
>
>The definition in the social logic of space is arbitrary.
>
>There is no guarantee that covering convex spaces so that axial lines
>intersect without repetition has anything to do with the way people draw
>axial maps in practice -in fact, convex spaces seem to have little to do
>with axial lines or axial maps.
>
>So the answer to your question is: he couldn't.
>
>
>>
>>I know axial line is drawn based on visibility, you can go where you can
>>see. But in my work, I need to analyze the traffic movement in the city's
>>street network. Is that justified to draw the lines based on reachablity?
>>Somewhere in the city, based on visibility, the axial lines should
>>intersect, but based on reachability they should not. For example, please
>>see the attached figure1, the axial line 1 should intersect with axial
>line
>>2 and 3 from the visibility point of view, but should not because street
1
>>is not directly intersected with street 2 and 3 (Figure 2), in other
world
>>car driving on line 1 can not directly shift to line 2 and 3. Which
>>principle should I use, visibility or reachability when I draw the axial
>map?
>>
>
>Again answers seem to vary: axial lines are straight lines on a map on
>mondays and tuesdays, but they are traced using visibility on wednesdays,
>thursdays and fridays.
>
>Look into the archives of this list and you will find people telling you
>to use both on different occasions.
>
>Rui
>
>
>>Any advice will be highly appreciated!
>>
>>
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