Latest Contributions by PatrickStevens

‎09-19-2012

Hello! OD cost matrix is used to find the distances between sets of locations. You can constrain the search based on a distance cutoff as well as a # of locations to reach from each origin. In your case, you are more interested in the distance between each CBOC and its parent VAMC. I think the more appropriate solver solution would be batch routing. Within a single Route analysis layer (or multiple, if you run into memory issues), load every CBOC, being sure to give the location a RouteName value that uniquely identifies that route. Perhaps you could use the CBOC id as the route name. Next, for every CBOC, load its parent VMAC, giving it the same RouteName you gave the CBOC. This will result in certain VMACs being loaded multiple times, which is fine, because they will have different RouteNames. Now, when you solve the analysis, you will get one route for each CBOC/VMAC pair.

‎09-12-2012

Hi, I have a question regarding web services used to distribute Live Traffic data and generating DTF files. I have tried to look for this services both on NAVTEQ and TomTom websites and have not found anything. I think that in documentation could be mentioned what type of service is it, so it could be easily searched. I tried to listen to web communication but target URLs have not given me any useful info. Is it then some special service, which is not mentioned in Services/Products on provider's pages? The Update Traffic tools for incidents and speed data downloads are configured for NavTeq and TomTom already. If you have a user name and password from those vendors, you can enter that in the GP tool. Then, you'll be able to use a traffic enabled network dataset with the downloaded data. To see the URLs used for the downloads, you can peek into the TrafficProviders.xml file. It is at: <ArcGIS Install Directory>\NetworkAnalyst\NetworkConfiguration\TrafficProviders.xml For me, that is: C:\Program Files (x86)\ArcGIS\Desktop10.1\NetworkAnalyst\NetworkConfiguration\TrafficProviders.xml And another question is if would be posible to add our own service to list in Update Traffic Data Tool (do some configuration). Or is it only limited to listed providers? I am asking since our region is not in provided and we could have posibility to make such a service of our own. Or would it be possible to make DTF file by ourselves? Instructions for adding your service to the Update Traffic tool is here: http://www.arcgis.com/home/item.html?id=e11126ea20e941bd9644046e62e2bdbe If you have any trouble with using the tool, post here and I'll help out.

‎08-31-2012

If you are truly just beginning to use Network Analyst, then before you do anything else, do the tutorial: http://help.arcgis.com/en/arcgisdesktop/10.0/help/index.html#/About_the_ArcGIS_Network_Analyst_tutorial/00470000005r000000/ It only takes an hour or so and goes through all of the basics of working with the software. So, assuming you did the tutorial, and assuming you are working in ArcMap and that you have a map with a service area layer and a country borders layer, do this: Right click on the Restrictions sub section of the Line Barriers class in your NA window. Choose Load Locations. Pick your country borders from the drop down called Load from. Click ok. It is similar to the Adding facilities step of exercise 4 of the tutorial.

‎08-30-2012

This comes down to two things, I think. First, do you have access to edit your network dataset? And second, should travel be completely restricted into the other country, or do you want to model the customs delays? Access to the network dataset If you can update the features of the network, then I would suggest adding a segment of road at each of the border crossings with a cost that includes the expected delay at that border crossing. This way, every analysis will include the delays properly. If you can only update the schema of the network, you can add a restriction attribute that either prohibits or avoids a specific country. In this case, you would have to turn the restrictions on or off for a given analysis. No access to the network dataset In this case, as Joe said, you will want to use barriers, but barriers come with a few caveats. First, they have to be applied to each analysis you do. You'll have to load them into every analysis layer you create that should respect the border barriers. Also, they can slow down your analysis. Depending on the scale of analysis you do, it might not matter, but there is extra processing done to ensure that a good path can be found near barriers. This only applies to hierarchical routes. In order not to disconnect the hierarchy with a barrier, the hierarchy filtering around the barriers is relaxed. This means more searching and more time. If you don't have access to your network dataset or you don't mind a little slow-down, then barriers are your choice. To completely restrict travel across borders, you can load country borders as line restriction barriers. To model customs delays, you can load additive point barriers at places where you would encounter border crossings. With additive barriers, travel will be allowed across them, but additional cost will be added to the route. This could be useful when a route with a customs delay is still faster than the next best route without the delay. Summary In summary, if maximum performance is a necessity and you can edit your network, then model the cost delays explicitely in the network. Otherwise, either use additive point barriers at the border crosses to model the delay, or use a line barrier to restrict travel across a border.

‎08-30-2012

The fix is only in 10.1+. It is not service packed back to 10.0.

‎08-30-2012

One more quick thing. The warning message is not just gone in 10.1, the thing we are warning about has been fixed. Measures are no longer disabled in the presence of additive costs.

‎08-30-2012

Hello, Kim! Sorry you are having so much trouble. Could you post what the error message is, if you are getting one? I'm not sure what you mean by saying it isn't using the network dataset. A Location-Allocation layer cannot be created without a reference to a network dataset. If the reference to the dataset is broken, then the layer will show up as broken in the table of contents (a red exclamation point next to the layer). Edit: typo

‎08-30-2012

I love that error message! That one was always my favorite, because of its length and complexity. It was like an error novella. We knew it was a problem, so it is gone now in 10.1. I'm not sure if it was service packed back to 10.0. I'll check that. As for what it means, your output shape is set to "True Shape with Measures". This gives you not just the route shape, but linear referencing M values along the shape. For example, for a 10 minute long route, you can see where you are 2 minutes, 5 minutes, 7, minutes along, etc. It used to be a problem when there was sudden additive cost along a route that should have M values. The error message lists "positive-impedance junctions, turns, or additive point barriers". Those are three examples of a place where you might add time to your route. For example, an additive cost barrier of 2 minutes turns your route from 10 to 12 total minutes. Previously, we couldn't handle generating Ms where, using the 10 minute route example, it went from 0 to 5 minutes, then had a 2 minutes additive point, then went from 7 to 12 minutes. When additive costs were encountered, we still solved the route, but we disabled M values in the output route shape. A warning would be generated letting you know that, even though you specified that Ms should be in the output shape, they will not be present. So, change your output shape to "True shape", instead of "True shape with measures." Then, you can turn warning messages back on.

‎08-22-2012

You are most likely looking for parameterized restriction attributes. Here is the help documentation on using those restrictions to model vehicle height/weight/length parameters. The doc suggests that you: Create a descriptor attribute called MaxVehicleLength. Create a restriction attribute called VehicleLengthRestriction. The restriction attribute should have a parameter called VehicleLength. Have the descriptor read in field values from your turn source with the maximum length vehicle allowed to make the turn. Say, "64". Have the restriction attribute be a function evaluator that checks if MaxVehicleLength < VehicleLength, the turn is restricted. So, for edges and junctions, your restriction attribute will always return false (not restricted). But for your Turn source, it should check the function evaluator to decide if the VehicleLength is greater than the MaxVehicleLength. You can set a default VehicleLength that will be used automatically. Then, in your analysis properties, for each analysis layer you work with, you can set a VehicleLength specific to that analysis.

‎08-07-2012

In addition to our normal bus fleet we have about 100+ special needs buses. I was planning the network to prevent the regular buses from turning onto cul-de-sac streets or others that would be difficult to turn around on. Since our special needs buses are shorter they can enter and turn around in cul-de-sac streets. My question is: Do I need a separate network for special needs over the district? Or is there a way to code the bus to allow it to enter cul-de-sac or dead end streets using the normal street network? You are working with what we call the "U-Turn Policy". There are 2 places where you can adjust u-turns. Here's a link to the help topic about it. You do not have to make changes to your network to use either of the properties. The first concept is called "Curb Approach". This will set how the vehicle approaches its stops. Should the vehicle arrive on the same side as the stop? And can the vehicle make a u-turn when it leaves the stops? The second concept is called "U-Turns at Junctions". This option governs how the vehicle behaves when traveling between stops. When the shortest path includes making a u-turn at an intersection or at a dead-end, can my vehicle handle this type of maneuver? Curb Approach is set in the properties of the stop itself. U-Turns at Junctions is in the analysis settings for any of the solvers you might use.

‎07-27-2012

You should be able to use them as barriers with some sort of impedance value. An alternative is creating turns, and they can get ugly... Barriers can be a viable solution, but I would recommend using your stop light points as a junction source in the network. Be sure that your stop light junctions are coincident with the source junctions for the affected intersections. Once the new junction source is built into your network, there are a couple of options on how to set the delays. If you have one generic value for the delay at every light (say 5 seconds), then use a constant evaulator on that junction source with a value of 5. If you have different delays for each light, then set up a field on your new junction source (say "Delay"), then use a field evaluator that reads the Delay value in. Constant evaluators are the fastest of the evaluators, as the value is set. Field evaluators are next fastest, as the values are processed when the network is built, not dynamically as the solve occurs. The caveat with this implementation is that your stop light delay will be incurred no matter what the maneuver at the intersection is. A left turn, a right turn, a U-turn, and driving straight through the intersection will incure the same delay coming from every direction that passes over the new junction. That same caveat would apply for the point barrier implementation as well, though. Turns are the most accurate solution, as they give you more refined control, but as you know, there can be A LOT of turns to digitize. Another potential solution is the Global Turn Delay Evaluator (GTDE). If, as dicussed previously, you have a generic set of delays depending on the type of maneuver, you can use this evaluator to specify them. The GTDE works based on type of turn (straight, left, right, u), as well as road designations (local, secondary, major). Your level of control can be as fine as a specific, generic delay for every left turn from a local road onto a major road, for example.

‎07-20-2012

I think you might have better luck at getting an answer on the Javascript API forum: http://forums.arcgis.com/forums/15-ArcGIS-API-for-JavaScript This forum is for Network Analyst functionality specifically.

‎07-20-2012

Hello! Here's a couple of questions to help narrow down what this issue might be: Could you post your code so we can have a look at it? What service are you connecting to? What is your input data? Are you getting any error messages or warnings on solve? Is there throttling on the service that limits the number of facilities? Any additional information would help us work this out. There is nothing inherent to the CF solver that would limit it to 10 facilities. Thanks

‎06-21-2012

Hello! I think you are looking at creating Service Areas using Network Analyst (Location-Allocation is a good option as well). Here is a link to the Service Area doc: http://help.arcgis.com/en/arcgisdesktop/10.0/help/index.html#//004700000048000000 and help with Network Analyst in general: http://help.arcgis.com/en/arcgisdesktop/10.0/help/index.html#/Types_of_network_analysis_layers/004700000032000000/ A good starting point is the Network Analyst tutorial: http://help.arcgis.com/en/arcgisdesktop/10.0/help/index.html#/About_the_ArcGIS_Network_Analyst_tutorial/00470000005r000000/ Service Area tutorial: http://help.arcgis.com/en/arcgisdesktop/10.0/help/index.html#/Exercise_5_Calculating_service_areas_and_creating_an_OD_cost_matrix/004700000060000000/

‎06-01-2012

Hello, Margaret! My apologies for the cryptic error message. This is a fairly low level message that could come from a number of places. Are you using barriers in your analysis? This string usually comes from an invalid value in the range of positions along an edge for a barrier. If you are using barriers, we'll track down exactly what the problem is and fix it. If not, we can start to look elsewhere.

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My Ideas

Latest Contributions by PatrickStevens

Re: OD Matrix: Destination Determined by Attribute

Re: Where to Subscribe to Live Traffic Data and Adding Another Provider

Re: Analysis with country borders factored in

Re: Analysis with country borders factored in

Re: Error message: Gaps have been detected...

Re: Error message: Gaps have been detected...

Re: Network Analyst Location/Allocation not using ND in 10.1...glitch?

Re: Error message: Gaps have been detected...

Re: Conditional restricted turns based on vehicle length

Re: Want to build a new Network

Re: Want to build a new Network

Re: When i load my page i get following warnings and not getting desired output..

Re: Closest facility is not working after adding more than 10 facilities

Re: Creating First Due polygons

Re: ERROR: The range of positions is invalid for this operation

Re: Getting properties from a custom evaluator

Re: U-turn policy question

Re: Rebuilding Network Dataset

Re: Script evaluators element variables

Re: Script evaluators element variables