Latest Contributions by JaySandhu

Since you are working with a very large number of "incidents", perhaps there is some other way to solve the problem. Can you elaborate what you want the overall solution to do? For example, do you route geometries/directions of the closest facilities? If not then you could be using the OD solver. Do the facilities need to be within a certain distance, say 20 miles? That is, can you put a cutoff? If indeed you can put a small cutoff, then you should turn off hierarchy if that is ON. And perhaps you have already run Calculate Locations on your 40 million points so that they can load quickly the next time around. Can you also say why the single thread with one zone did not work perfectly for you? Jay Sandhu ... View more

The contents of the network dataset folder are in a binary proprietary format. However you can access the attribute information of a network dataset from python using the describe function. More here: http://help.arcgis.com/en/arcgisdesktop/10.0/help/index.html#//000v00000055000000 With 10.1 there are additional python functions for network analyst. You can read more about that here: http://resources.arcgis.com/en/help/main/10.1/index.html#//01mr00000012000000 Jay Sandhu ... View more

The Route sub-layer of a route analysis layer is a feature layer. You can simply right-click it in the TOC and choose Data and then Export Data to write to shape file. Alternatively you can use a GP function Feature Class To Shapefile and similarly you can export to KML by using the Layer To KML tool. For symbology, you can use the Map To KML tool to export a map document that contains both the geometry and symbology as well. Jay Sandhu ... View more

The help on Minimize Facilities here: http://resources.arcgis.com/en/help/main/10.1/#/Location_allocation_analysis/004700000050000000/ Says Minimize Facilities is the same as Maximize Coverage but with the exception of the number of facilities to locate, which in this case is determined by the solver So it is a set covering but what it does is starts with an estimate of the number of facilities needed and internally calls a variation of maximize coveraege to quickly and intelligently narrow down the number of minimum facilities needed and then finishes by running maximize coverage with the minimum facilities needed to populate the results. Regards, Jay Sandhu ... View more

Li, The ArcGIS Location-Allocation does not use any integer programming to solve this complicated combinatorial problem. It uses heuristics. The LP approach cannot be used to solve lvery arge problems and can take too long to converge to a good solution. Details about the algorithm are listed here: http://resources.arcgis.com/en/help/main/10.1/#/Algorithms_used_by_the_ArcGIS_Network_Analyst_extension/004700000053000000/ Jay Sandhu ... View more

It is likely that the four destinations are on restricted edges. You could bring up the properties of the OD layer and on the Network Locations tab at the very bottom turn on the "Exclude restricted portions of the network". Click OK. Now, in the NA Window, right-click the Destination and choose Recalculate Location fields and then choose unlocated ( I am assuming that you have four destinations with this status). If not, you could choose All. Re-solve. If it still cannot find paths to these locations, try turning of all the restrictions and see if that will work. Jay Sandhu ... View more

You  can do this with the Route solver where you can load the Origin and Destination pairs with a common ID mapped to the ROUTENAME property. It has been answered many times in the forums. Search on ROUTENAME, e.g., here: http://forums.arcgis.com/threads/60480-question-about-creating-routes-in-network-analysis?highlight=routename Jay Sandhu ... View more

You could look at the following user written tools that contain some minimum spanning tree tools: http://www.nrel.colostate.edu/projects/starmap/funconn_index.htm Jay Sandhu ... View more

You can bring up the properties of the service area layer and on the line generation tab, turn on the Generate Lines and re-solve. Are the roads that you added showing up in the service area lines? The polygon will only cover the lines that were traversed by the service area. If they are not traversed then their is some connectivity issue, restriction, etc that is causing the problem. Jay Sandhu ... View more

This spike looks very simillar to a math issue we resolved as part of the 10.1 release. If you can upgrade to 10.1 then the issue should go away. Jay Sandhu ... View more

It means there is no path from any of your origins to the destinations. Most likley the destination is on an unreachable location. This could be due to some restrictions or network connectivity issues. Jay Sandhu ... View more

When you do Add Locations, you have to specify what kind of locations you are loading. By default it is set to the first choice. In the case of Closest Facility that will be "Facilities". So open up the second load locations where you want to load the incidents, and the second item on that menu is titled "Sub Layer". Change that to Incidents and save your model and re-run it. Jay Sandhu ... View more

Service Area polygons are drawn around the edges that can be reached within the specified break values. You are using Breaks - 250, 500, 750, 1000 miles but the line deep purple lines (I presume that this is the service area lines) show that not much of the network was reached. So you most likely have disconnected portions of your network that is preventing the service area to reach up to the 1000 miles towards the East. That is why you are getting only an elongated north south service area polygons. Note that the "disconnected" portions may be caused by topology issues or restrictions. Jay Sandhu ... View more

It could be that the location is unreachable due to restrictions or network connectivity. If you remove one of the overlapping points, can you reach the other one? Jay Sandhu ... View more

Overlapping points are supported. You can create a closest facility layer, enter 1 facility and then copy paste it to duplicate it. Now enter a facility location and then copy/paste it as well. Set the CF layer to solve for 2 closest. Solve. You will get 4 routes output. You can even have the same set of two facilities entered as Incidents (that is all 4 locations overlap). Solve and you will get 4 routes output but they will have 0 travel cost/length. If this is not the scenario you are running into then perhaps you can provide some more details. Jay Sandhu ... View more