Rank Locations by Proximity to Different Service Type Points

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08-14-2012 10:20 AM
JamesLabate
New Contributor II
Dear All,
I have a simple objective of looking to rank a facility location by its proximity to six separate services offered at separate locations. So, for example, a facility that has 5 or 6 of these services within a quarter mile walking distance would be classed "best" etc. I have a decent street file that successfully built into a Network Dataset. My facilities file is nothing more than a buildings point file with no fields that relate to the line file. How do I create the relationship bertween the points and the street file? I'm looking to create fields in the building/point file such as "PosAlong; Side of Edge; SnapX; SnapY; Distance.

I found a toolbox online called Urban Network Analyst (UNA) - http://cityform.mit.edu/projects/urban-network-analysis.html. This appears to do what's required but I need to get my input buildings file in proper shape.

First: Is UNA even necessary? Is there an existing tool in the ArcMap toolbox that can accomplish the same thing? i.e. calculate "Reach"
Second: How can a point file be processed to "correspond" to a street network as I described above.

Thanks in Advance,
Jim Labate
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5 Replies
JaySandhu
Esri Regular Contributor
You can use the GP tool Calculate Locations to add the "PosAlong; Side of Edge; SnapX; SnapY; Distance" fields. For it to work you need to create a network dataset on your streets. More help here:
http://resources.arcgis.com/en/help/main/10.1/#/Calculate_Locations/004800000006000000/

As far as trying to find a rank, you could use either the OD or the Closest Facility solver to solve for all services within a quarter mile walk and it will return the number of features (destinations or facilities) found. You can then assign a rank based on this number. More help here:
http://resources.arcgis.com/en/help/main/10.1/#/Closest_facility_analysis/00470000004n000000/
and
http://resources.arcgis.com/en/help/main/10.1/#/OD_cost_matrix_analysis/00470000004r000000/

Jay Sandhu
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JamesLabate
New Contributor II
Jay,
Thanks very much for the response. Calculate Locations tool created a good working feature class with all the location fields necessary to correlate to my street network file. They both reside in a FGDB Dataset along with a successfully built Network Dataset derived from my street file.

Unfortunately, when I attempt to add only the Shelter features from my Buildings feature class to my Network Analysis Layer's Facilities sub-layer -  by using the Search Query option in the Add Location tool - Add Locations adds all the features in the feature class. The SQL expression the Query Builder creates is being ignored for some reason.  The buildings feature class certainly has a type field with "Shelter" records to select. Everything appears fine and I simply want to add X # of Shelter features as Facilities and X # of say Foster Care offices as Incidents. The Buildings feature class is a Source for the Network Dataset and appears in the Add Location tool's dialogue at the bottom - as a choice for the search query option. The expression is simply Type = 'Shelter' but it has no effect. What am I missing here?

Thanks, Jim
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JaySandhu
Esri Regular Contributor
The search query option is not to load a subset of the locations with Add Locations. It is to specify a subset of the network street features to be used for locating the input points. For example you may want to exclude locating on highway ramps or interstates. More on this capability here (see the search query portion towards the end):
http://resources.arcgis.com/en/help/main/10.1/index.html#/Add_Locations/004800000005000000/


So use a tool like "Select Layer By Attribute" to first select the relvant points to load and then pass that selection to the Add Location tool. Help here:
http://resources.arcgis.com/en/help/main/10.1/index.html#//001700000071000000

Jay Sandhu
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JamesLabate
New Contributor II
Jay,
Thanks again. Seem to be going station to station here though.

My Objective is again, to select two building types from a single point file (that has had its locations calculated using my built network dataset) and add each selection to a Closest Facility network analysis layer: one as the facilities; one as the incedents. Very basic.

The first Select and Add sequence goes fine using the Select Layer by Attribute(SLBA)  and the Add Locations tools respectively.

Making the second selection and add is problematic. I clear the selection of the Buildings file and restart the SLBA tool, but Bldg. point file no longer appears in the tool's "Layer name or table View" drop down. If I try to path to it the tool's filter doesn't see File Geodatabases. I simply want to repeat the sequence and select and add anothet subsert of building types to the Incidents class.

I have forced it by creating a separate featureclass of the subset I'm looking to add and 1) adding it as a source to the Network Dataset; 2) Adding it to the Incidents sub-layer. But even then when I hit the "Solve" button on the Network Analyst toolbar I get no routes - just the error: "No Facilities at/in Location(all) in Incidents" Does that mean that the Incidents never added properly.

So to recap I need to:
   Select and Add Incidents
   Confirm that simply hitting the "Solve" buttom in the NA toolbar is what you were refering to when you said"Closest Facility Solver"
The help link you sent was making reference to SDK and Visual Studio. That is not what is required to at least get routes is it?
If I  need to some how manually tally the routes to rank them then that's the best I can do.
Thanks for all your help
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JaySandhu
Esri Regular Contributor
I am not sure what you are doing from start to finish.

You can follow Tutorial 4 on Closest Facility.

Basically you need to:

Create a Closest Facility Layer, and set up properties like find 1 closest
Add Incidents
Add Facilities
Solve

Make sure when you Add Incidents or Facilities that you pick the approriate sub layer (facilities or incidents)

If you are unable to get the CF layer properly configured, then please post a step by step list of what you did.

Also are you doing this in a model or by calling each tool individually?

Jay Sandhu
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