Reach returning values of 0

[efo...@aucklanduni.ac.nz]

Hi,

Firstly I'd just like to say thanks to all involved in creating this great toolbox :)

However, I have encountered a slight problem whereby a small number of my input points are returning reach values of 0 (attribute table example, below).

At first I thought having fractional values in my weight field may be causing some sort of problem. Rounding all values to the nearest whole didn't change anything -- the same points all returned values of 0.

I do not believe it's a problem with my (basic) network. The below screenshot is of the 600 m service area of the one troublesome point (the same one as in the above screenshot, while the point to its immediate NW is the second, working, point in my data), as created by the Network Analyst extension. Everything seems to be working fine as far as I can see.

Could my troublesome points perhaps not be properly snapping to the network for whatever reason(s)?

Any help at all would be much appreciated, and my apologies if this has been covered elsewhere, or it's a simple solution I'm missing.

Regards,

Euan

[Andres]

Hi Euan, could you pls check for me if the two other points inside the red circle i have added get reach values as expected? Andres

HI Euan, can you please check if 

[efo...@aucklanduni.ac.nz]

Hi Andres,

The two points also returned reach values of 0.

[Andres Sevtsuk]

it seems to be an OD cost matrix issue for points that snap to the extremities of network segments. if you move these points to a nearby position, where they dont snap to the enpoint of a cul-de-sac street, that might resolve it for now. We would have to look into the code to address this properly.

Best, Andres

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[efo...@aucklanduni.ac.nz]

I'll look in to making the manual changes, then. Many thanks for the help and clarification.

Regards,

Euan

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[Nayomi Kankanamge]

Hi!

I went through your question and seems like you can help me in regard to my question. In your attribute table I noted that there are Landuses and House pop.. Can ypu please tell me how did you receive these information and whether you typed them or not..

[efo...@aucklanduni.ac.nz]

Hi Nayomi, 

To quickly answer your questions, land use was acquired from the local council/government, while population was derived from aggregate census data -- which is why there's odd values like a residential population of 1.58036 people. The fields were automatically populated via spatial joins and field calculations.

[Nayomi Kankanamge]

Dear Sir/madam, 

Thanks a lot for your question. If you don't mind I would like to continue this discussion since I have lots of things to be clarified. I am planning to do a research using UNA tool. Thus, I think I need to clarify those. If so, it is appreciated if you could help me. 

re.. population. It's fine. But we need information in building wise.. isn't it. Of course, local authorities will give the population in local authority wise. How can I get the information in building occupancy in a large area. I noted in your attribute table exch building number had a population value.May I know how you get it please? 

Best Regards!

Nayomi Kankanamge

Instructor

BSc. (Hons) Town & Country Planning
Department of Town and Country Planning

Faculty of Architecture

University of Moratuwa

Sri Lanka
Office: +94 112650921
Mobile; +94 778732310

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[efo...@aucklanduni.ac.nz]

Hi Nayomi,

I'm happy to try and help you out as best I can. Though it might be best to continue by email instead of by taking this thread further off topic.

My email is: efo...@aucklanduni.ac.nz

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