Latest Contributions by JaySandhu

At version 10.0, only VRP and Route solver support a start time. In 10.1, all the other solvers including CF and OD support it as well. So you could get on the 10.1 beta program (going on currently) and use that software to solve with start times! Jay Sandhu ... View more

It's not simply re-building but making sure that there are no point feature sources in your network dataset. You can bring up the properties of your network dataset and in the sources tab you should have an edge feature source and a system junction source. Anything else should be there only if you want it to be there. If the point barriers are showing up there then remove them and re-build. Jay Sandhu ... View more

That is not true. As I said before, most likely you have these points as a point source in your network and that is making it locate on unconnected features. Not sure if you tried removing these sources from your network and rebuild the network and trying it again. Point Barriers, Stops, Facilities etc do not need to touch the lines. If that is the only way you can make it happen then I suggest that you contact Esri tech support and have them look at your data. Jay Sandhu ... View more

Holes basically means their are edges that are not being traversed within the given break value. Normally you will get holes when you choose the Detailed method. With the Generalized method the number of holes should be minimized or non-existant. If you want the see how far the edges were traversed then turn on the line generation for the service area and the lines will also be generalized. Jay Sandhu ... View more

Perhaps your machine has 2 GB not 2 TB amount of memory. Regardless, 418 incidents and 32 facilities is not a big problem and you should be able to get an answer without runing out of memory. What network dataset are you using and how far apart are the incidents/facilities. Perhaps you can make sure that hierarchy is ON or if the hierarchy is not ON, then make sure a distance cutoff is in place so that in case there is no path between some incident/facility combination it is not searching an entire nation wide network with an exact solve and running out of memory. Regards, Jay Sandhu ... View more

If the goal is to find one path from a point in file A to a point in file B then this type of routing is available out of the box. No need for python loops, etc. Search the forums on the keyword "routename" and you will see previous posts on how to solve this in a single route layer. E.g., see: http://forums.arcgis.com/threads/14884-Distance-from-residence-to-work-for-7000-participants?highlight=routename If the goal is to find a matrix of all distances between 1200 by 1600 points then use the OD Cost Matrix solver. Online doc is here: http://help.arcgis.com/en/arcgisdesktop/10.0/help/index.html#/OD_cost_matrix_analysis/00470000004r000000/ Jay Sandhu ... View more

Check your spatial index on the feature classes that you are drawing. if it is a bad index it may have to fetch all features every time you pan/zoom. You can verify a "bad index" by doing an identify on a feature and see how long it takes. If it is not quick then it is a bad index. Jay Sandhu ... View more

You can use the Network Analyst solver OD Cost matrix to load all you accidents as origins and destinations. Then bring up the properties of the OD layer and set a cutoff of 100 meters (assuming you have a length impedance attribute in meters) and turn off hierarchy if it is on. Then solve. The output lines table will have a list of distances between each accident. There is a DestinationRank field that shows how many destinations were found for each Origin. You can select rows based on DestinationRank > 8 and then use this to further qualify if they happen to be within your time frame. Hint: Add a date field to the Origins/Destination attribute tables and then at LoadLocations time map the date/time to this date field so that you have access to this information after your solve. Jay Sandhu ... View more

Brian, In case you have not seen this sample, you may be interested to see the code on traversing the network for checking connectivity here: http://help.arcgis.com/en/sdk/10.0/arcobjects_net/conceptualhelp/index.html#/How_to_programmatically_traverse_a_street_network/00010000023n000000/ Regards, Jay Sandhu ... View more

The build log files are kept in the temp folder. So go to your %TEMP% folder in explorer and see the contents of the BUILD.TXT and/or BUILDERRORS.TXT to see what was done. Perhaps that will give a clue to why the network is not building. Another thing you can try to do is create a new file gdb, feature dataset and then copy the network dataset to it and re-build and that may provide some additional information as well. Jay Sandhu ... View more

This is quite easy to do using "linear referencing". Create a service area solver, add one or more facilities. Bring up the properties of the service area layer and on the polygon tab turn off Polygon Generation and on the Line Generateion tab turn on the lines and ALSO click on Generate Measures. Close the properties and solve. You will not get service area lines showing where you can reach in the default break value e.g. 5 minutes. Now create a text file (csv format) as follows and save it in as WalkSymbol.csv "FacilityID", "Measure", "Symbol" 1,1,1 1,2,1 1,3,1 Add this csv file to ArcMap. The under the File menu, choose Add Data and then select the Add Route Event. This will bring up a form. It should be filled in as needed, that is, Route Reference should be your service area "Lines" feature class, the Rotue Identifier should be "FacilityID", Event Table should be "WalkSymbols.csv", Route Identifier should be "FacilityID", Point events should be checked and the Measure should be "Measure". Next step is very important: At the very bottom is the Advanced Options. Click on that and this opens another form. Make sure to choose the second option "Point events treated as multipoint features" and then also check at the bottom "Apply these settings to all subsequent ArcMap sessions". Click Ok on both forms. This will now display points at every 1, 2 and 3 minutes. You can bring up the symbols and change them as necessary. See my attached screen shot showing service area from two locations with symbols at 1, 2 and 3 minute drivetime.s Jay Sandhu ... View more

I think it may not work with one million patients. I will suggest that you split it into 10 solves of 100,000 patients each, write out the results and combine them at the end. Couple of other things you can do is to run ArcGIS on a windows 64 bit machine with 4 GB RAM. On a 32 bit OS, the maximum memory it can use is 2 GB but on a 64 bit OS it can use 4 GB. If you have multiple cores, like a quad core machine, you can use the GP background processing to run more than one solve simultaneously to speed it up. For example, run two solves of 100,000 each. Jay Sandhu ... View more

If you only need to know the location and distance then use the OD Cost Matrix solver. But if you need the actual route to be shown then continue to use Closest Facility. To solve your problem of finding ONE closest hospital, set a cutoff distance or time, say 60 miles or 60 minutes. (i.e.. what ever is reasonable in your case). Turn off hierarchy. Set number of facilities to find as 1. Solve. it should work with 50,000 incidents and 10,000 facilities. If it does not, can you report back to how far it gets or what error message is reported. Also, If you are using these points over and over again, I will suggest that you run the GP tool, Calculate Locations on your hospitals and patients so that you can load them by network locations (not geometry) into a new network layer. Jay Sandhu ... View more

Are you trying to do routing for a transportation network like a street network? I ask this because you mention upstream and downstream paths which are more typical for river, sewer, electric type networks. If you need to work with these kinds of networks then you need to construct a Geometric Network on your data and use the Utility Network Analysis toolbar. if you have a transrportation network then you need to create/build a Network Dataset and use the Network Analyst toolbar to create a route layer and solve a path on it. And you can access the same solvers on the server. Jay Sandhu ... View more

If you add your network dataset to ArcMap, create a Route layer and then can you add the point barriers by clicking on the map? i.e. Is the problem only when you use the "Load Locations" or also when you click on ArcMap? Have you tried increaing the search tolerance from the default 5000 meters to something larger, say 20000 meters? Jay Sandhu ... View more