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Waafa

The detailed reason is that the first reduction from the All lines map retains lines that have different connections. In this case you have a relatively wide and continuous curving space at the top left of the plan. As you move round the curve new views through to the distance open in front of you and disappear behind you. This leads to a lot of interconnected lines in the space. The shear weight of numbers attracts shallowness in the graph to this alignment. It is for this reason that the standard approach is to use the fewest line map which avoids this effect. 

The advantages of this approach is that they are algorithmic and well defined. Other representations often rely on human intervention and so cannot make that claim. 

Alan

Sent from my iPhone

On 25 May 2018, at 13:22, miguel serra <[log in to unmask]> wrote:

Dear Wafaa,

I take that you are using Depthmap's feature for automatically creating axial lines, which is highly dependent on the shape of the open space representation that you have provided to Depthmap, in the first place. You don't show that on your pictures. But let's assume that you are using a correct open space representation.

The fewest-line (subsets) map, as the name indicates, is really neither an all-line map nor a fewest-line map. It is just an intermediate step of the algorithm that creates the fewest line map, without structural relevance and prone to contain imbalances of the type you have encountered. In your example, there is a very high concentration of redundant lines at the curve on the top left of the image, which obviously are much more connective than the rest of the lines in the map. This is why that area is highlighted, overshadowing the rest of the system.

This is an artificial effect, that is corrected in the fewest-line map (which retains only the longest lines). Now, if you try and compare the results of the all-line and the fewest line maps (not the subsets map), you'll probably find out that the results are much more akin.

As Prof. Bin Jiang says, results will always depend (at least to some extent) on the type of street-network representation adopted. But I wouldn't be so bold as to immeadiately state that one type of representation is better than the others. In fact, the 'named streets' method depends on an highly contingent factor, i.e. the stability and structural relevance of toponimical designations, which changes dramatically from one city to another. This is something that does not happen with axial lines, as fuzzy as their definition may be. 

Best regards,
Miguel
          

Em sexta-feira, 25 de maio de 2018 11:38:36 GMT+1, Bin Jiang <[log in to unmask]> escreveu:


Dear Wafaa,

The reason lies on the issue of what is the best representation of the underlying configuration. For a city as a whole, it is best represented by individual natural streets rather than fragmented axial lines. Axial lines are of use if you concentrated on part of a city, or when there were no way of generating natural streets.

Herewith a piece of message I shared with AXWOMAN  users, and it may help address your concern:
Axwoman can auto-generate axial lines, but natural streets are much better than axial lines at a city scale for illustrating the underlying scaling or for predicting traffic flow:
https://www.researchgate.net/publication/1918773_Self-organized_Natural_Roads_for_Predicting_Traffic_Flow_A_Sensitivity_Study
https://www.researchgate.net/publication/1764726_Street-Based_Topological_Representations_and_Analyses_for_Predicting_Traffic_Flow_in_GIS
http://giscience.hig.se/binjiang/axwoman/TutorialNaturalStreets5PDF.pdf

I just delivered a talk to CSUM 2018, and it is closely related to the issue you raised: https://youtu.be/pVUquwnwcvc
If you are tired of oral presentation, herewith the related text: https://www.researchgate.net/publication/324819522_Editorial_Spatial_Heterogeneity_Scale_Data_Character_and_Sustainable_Transport_in_the_Big_Data_Era

Thanks and cheers.

Bin
On 5/25/2018 12:10 PM, [log in to unmask] wrote:
Thank you very much 

On Fri, May 25, 2018 at 1:06 PM, [log in to unmask] <[log in to unmask]> wrote:


Hello, I’m Architect Wafaa 


I have a question, I analysed this settlement below by using Depthmap software program and when I reduce all fewest line map (minimal) in comparison with fewest line map (subsets) I found there is a different analysis in the integrated axial lines( completely differen as shown below)



Regards 


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Sincerely:
Architect: Wafaa Anwar sulaiman Goriel
BS.c& MS.c in Vernacular Architecture & Architectural Design
Faculty of engineering & Applied science,
Architecture department, University of Duhok.
Website: www.uod.ac/   
Kurdistan Region, Duhok/ Iraq 

Address:
University of Duhok
Website: www.uod.ac 
Phone no.: (062) 722 7060
  
Zakho St. 38
1006 AJ
Kurdistan Region - Iraq



--

-- 
Sincerely:
Architect: Wafaa Anwar sulaiman Goriel
BS.c& MS.c in Vernacular Architecture & Architectural Design
Faculty of engineering & Applied science,
Architecture department, University of Duhok.
Website: www.uod.ac/   
Kurdistan Region, Duhok/ Iraq 

Address:
University of Duhok
Website: www.uod.ac 
Phone no.: (062) 722 7060
  
Zakho St. 38
1006 AJ
Kurdistan Region - Iraq

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--------------------------------------------------------
Bin Jiang
Division of GIScience
Faculty of Engineering and Sustainable Development
University of Gävle, SE-801 76 Gävle, Sweden
Phone: +46-26-64 8901    Fax: +46-26-64 8758
Email: [log in to unmask]  Web: http://giscience.hig.se/binjiang/
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Associate Editor: Cartographica
BinsArXiv: http://arxiv.org/a/jiang_b_1
Axwoman: http://giscience.hig.se/binjiang/axwoman/
Geomatics: http://giscience.hig.se/binjiang/geomaticsprogram/
RG: https://www.researchgate.net/profile/Bin_Jiang3

Högskolan i Gävle

Högskolan i Gävle, 801 76 Gävle • 026 64 85 00 • www.hig.se

För en hållbar livsmiljö för människan

University of Gävle, SE-801 76 Gävle, Sweden • +46 (0) 26 64 85 00 • www.hig.se

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