FYI
________________________________________
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.
On Tue, 5 Jun 2007 13:59:24 +0100, Professor Bill Hillier
<[log in to unmask]> wrote:
>Rui, in syntax every axial line is drawn with respect to all others,
>and you can only be sure that any line is a correct one by checking
>it with reference to the system as a whole. The proper question is:
>'Are axial graphs unique', that is, is there a correct one for every
>urban system. I believe we showed two ways in which we could be sure
>of this in my Rejoinder to Carlo Ratti. At that time - I think on
>this mailbase - I challenged sceptics to show a case of a settlement
>where, given that we agreed what was to be mapped, the definitions we
>offered allowed more than one interpretation of the axial graph. So
>far we have had no candidates.
>
>Anyway, until someone shows that axial graphs as we defined them are
>not unique, and that there is not a 'correct' graph for each
>settlement, we can say with reasonable confidence that an axial line
>is any line that is a member of the set making up a correct axial
>graph. In all other respects it is just a line drawn on a map.
>
>Since we cannot limit its length, connectivity or straightness, which
>are the only intrinsic properties a line has, it is clear that we can
>only define axial lines with respect to the system of which they form
>a part, that is, with respect to the extrinsic, not intrinsic,
>properties of each line.
>
>So if you are interested in the rigour or otherwise of axial mapping,
>your question seems to be the wrong one. It really should be: Do
>settlements have unique axial graphs ? To expect to build such a
>graph from some kind of essentialist definition of a line, however
>derived, is really a 'reifying slices' error.
>
>By the way, I don't like beer. But Portuguese wine is another matter
>if you have access to a good producer ! - Bill
>
>
>
>
>At 11:06 05/06/2007, you wrote:
>>Free pints for life to the first who can give an unambiguous definition
>>of "axial line" -and that's out of a post-doc's salary, so you see how
>>sure I am that this is mission impossible!
>>
>>C'mon Alan!
>>
>>Rui
>>________________________________________
>>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.
>
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