Latest Contributions by MelindaMorang

Streets that are expected to connect have to have either a) and endpoint or b) a vertex on both street features at the location where they touch, depending on whether your connectivity policy is End Point or Any Vertex.  Please read this doc page to understand what those mean: ArcGIS Help (10.2, 10.2.1, and 10.2.2) If your connectivity is Any Vertex and you just need to do a batch vertex insertion at locations where your streets touch, you can run the Integrate tool.  Make sure you make a back-up copy of your data first, as Integrate actually modifies the input features by moving them slightly.  You can set the tolerance to be small or tiny, though, so it won't move stuff much or at all and will instead just add vertices.  The one problem here is locations where you have an overpass and the crossing streets are actually not supposed to connect.  You might have to manually fix those areas. If your connectivity is End Point, you may have more trouble.  If you split existing features down the middle so that they have end points, you risk messing up attributes that need to be carefully apportioned when the street feature gets split.  For instance, if you have a field called "walktime" and you split a street that has a value of 5 minutes in the walktime field, it would be incorrect for the two split parts of the street to both have a value of 5 minutes.  So, if you have End Point connectivity, you either need to split a lot of features very carefully, or you need to switch to Any Vertex connectivity and run the Integrate tool. ... View more

It's probably a connectivity problem in your network.  Suppose you have a small chunk of your network that's disconnected from the rest of the network.  If your stop snapped to a network edge in that disconnected portion, then it could be that it isn't possible to travel 800 meters.  The maximum distance you could travel was 169m. Use the Network Identify tool (on the Network Analyst toolbar) to click around on the network edges in the vicinity of the problematic points.  In the pop-up Network Identify box, you can see what other edges are connected to the one you clicked on, so this is an easy way to identify connectivity problems. In order for network edges to connect, there needs to be either an endpoint or a vertex on both features at the location where they touch, depending on your connectivity policy.  You can read more about network connectivity here: ArcGIS Help (10.2, 10.2.1, and 10.2.2) ... View more

A geometric network isn't the same thing as a network dataset.  Geometric networks are usually used for utilities (power, water, etc.), whereas the network dataset is specifically for roads and used in the Network Analyst extension.  Could that be the problem? ... View more

Hello, CY. At this time, there are no plans for a tool to create a GTFS dataset from ArcMap.  One of the main reasons is that most of the data included in the GTFS dataset is not inherently geographical.  stops.txt is the only required file that contains any geographic information at all (the stop locations).  The only other file that includes lat/lon points is shapes.txt.  The rest of the files are a large set of related tables containing information about the schedules.  We don't have any tools to help with scheduling, and table manipulation is probably easier outside of ArcMap. ... View more

You can write such a script using a Geometry Polygon object and some search cursors. See the code sample at the bottom of this page: ArcGIS Help (10.2, 10.2.1, and 10.2.2) ... View more

Thank you so much for your input, Rell. Regarding points that still fall outside the range specified: If this is a consistent problem for you, you can just increase the search tolerance (range).  Is there some other reason increasing the search tolerance wouldn't work for you? Regarding the Ignore Invalid Locations setting: The current ArcMap 10.x behavior is as follows: If "Ignore Invalid Locations" is checked True: The solve succeeds, but it throws a warning message saying 'Location "[blah]" in "Stops" is on a non-traversable network element position.' That location is simply skipped, and the route will bypass it completely. If "Ignore Invalid Locations" is unchecked False: You get the same warning, but the solve fails, and no output is produced. You can also uncheck the "Terminate on Solve Error" option. The tool now always succeeds in running, even if no output is actually produced because the solve failed. So, to summarize: Regardless of your "Ignore Invalid Locations" setting, you can always extract the features that caused the problem from the warning messages.  If you want solve output to be produced, you need to set "Ignore Invalid Locations" to True.  Does that answer your question? The proposed new behavior wouldn't change the "Ignore Invalid Locations" setting, but it would make it much less likely that points would be invalid in the first place.  They wouldn't locate on restricted areas to start with, and if the restrictions and barriers changed after they were located, they would be relocated automatically at solve time. ... View more

Hi Simon.  No, this is not possible with the OD Cost Matrix solver.  The reason OD Cost Matrix is fast is precisely because it doesn't store the "traversal result", the actual network edges and junctions used.  If you need to extract that information, you need to use the Route or Closest Facility solver. ... View more

Topology of the input features is only one possible cause of a poorly-connected network.  Please see the link in my post above about network connectivity.  It could be the way your connectivity groups are set up or your connectivity policy.  Maybe you're using End Point connectivity when you should be using Any Vertex, or maybe you have override vertices but their connectivity policy isn't set to Override. ... View more

I wasn't sure what you were referring to when you asked about the timeframe for "this" to be implemented.  Are you referring to the ability to create and/or edit network dataset properties in python?  If so, I can't answer that question except to say that we have no definitive plans to provide that functionality at this time.  We are aware that many users want this functionality, however.  It's on our radar. ... View more

Hi Natalie.  Let me try to address each of your problems individually below. Hierarchy Hierarchy is a way of speeding up lengthy, long-distance route calculations by ignoring small local roads and preferring highways.  It is not fully guaranteed to give the true shortest path, but it does a good job most of the time.  If you solve without hierarchy, all the roads will be searched until the true shortest path is found.  Consequently, your observation that some of the routes created were obviously not the shortest path when you were not using hierarchy makes me think that your network has some connectivity problems.  If you're not using hierarchy, the Closest Facility solver will always return the shortest path through the network.  If the shortest path looks wrong, it's probably because the network has some problems. Network dataset problems Here are a few common network dataset problems that cause incorrect results: - Your impedance attribute isn't set up correctly, so all roads have 0 impedance (then it doesn't even matter what roads are used in the route because it costs nothing to travel across any of them). - Your road features don't actually touch at intersection points.  Maybe when they were digitized, you didn't have snapping turned on, and the road endpoints just don't coincide, so it's not possible to travel across intersections. - Your road features touch, but the points of intersection don't have a vertex (if you have an Any Vertex connectivity policy) or an endpoint (if you have an End Point connectivity policy).  In this case, the roads appear connected but aren't actually logically connected in the network. This documentation page provides further information: ArcGIS Help (10.2, 10.2.1, and 10.2.2) Solve not creating a path to all facilities You definitely need to set "Facilities to Find" equal to the number of facilities you have if you want a route to be generated to all of them for each Incident.  If some routes still aren't being generated, it's possible that no route was found in the network (which should generate a warning message).  That would be another symptom of a network dataset problem. Other things to think about - If you're having trouble with your network dataset, and if you don't need to use your own street data (for instance, you have your own forest roads that you've added), you could use our online Closest Facility service.  You would be charged credits from your ArcGIS Online account, but it would save you the trouble of creating and managing your own network dataset.  You can connect to the online services through ArcMap as described here: ArcGIS Help (10.2, 10.2.1, and 10.2.2) - If you just need the travel time or distance between your points and not the actual routes taken, you should use the OD Cost Matrix tool instead of Closest Facility.  It will run much faster, and it defaults to finding all OD pairs. ... View more