Latest Contributions by JaySandhu

If the goal is to compute distances from each grid centroid to eveything within 6 miles then there is no need to first create service areas to select them. Create an OD layer and first load your centroids as Origins and then all the points as destinations and then set a 6 mile cutoff on the OD layer properties and solve. In fact since the 6 mile cutoff is there, turn off Hierarchy and it will solve very quickly. The output Lines table will have distances from all centroids to points within 6 miles (their may be overlaps...) Another hint, depending on what kind of "accessibility" numbers you need..look at Location-Allocation with the Maximize Market Share model. Set your centroids as Facilities with the REQUIRED status, load your points as demand points and then you can choose the maximize market share, set a cutoff of 6 miles, chose a power or exponential decay and set an exponent and solve for all required facilties. It will have computed spatial interactions between all pairs...of course this may not be what you need. Jay Sandhu ... View more

If you just installed ArcGIS, then check the source (DVD) to find the tutorial install and use that to install the network analyst tutorial data. The tutorial is normally installed in a folder under C:\Arcgis Jay Sandhu ... View more

For some reason it seems like the analysis is ignoring several streets in the analysis, thus shaping the polygons completely wrong. I've added a screenshot of the areas in question. It is most likely that the streets that are getting ignored do not connect to the other streets. So check if they are in fact connected (use the network identify tool on the NA toolbar (second icon from right). Note that they may be connected but have a restriction or high cost so that they are not reached. The other reason could be that you set the properties of the service area polygon (on the polygon generation) to exclude some set of line source features. If that is the case, un-check the excluded sources. Jay Sandhu ... View more

You can achieve this with the Service Area solver with the Lines option. So create a new service area layer, and bring up the properties of the service area layer. On the polygon tab, turn off Generate polygons and then on the Lines tab, turn on Generate Lines. Then on the Analysis tab, choose your impedance as lenght or time and set the break value to 4 km or 10 minutes as needed. Close the properties. Now add you facility and solve. You will get all the lines that can be reached within the specified break value. More on service area here: http://help.arcgis.com/en/arcgisdesktop/10.0/help/index.html#/Service_area_analysis/004700000048000000/ Jay Sandhu ... View more

You need to change the curb approach property of the individual stops to say "No U-Turn". You can do it for all of them by opening the Stops Attribute table and then using the field calculator to set the curb approach to the value 3. And then re-solve. You can read more about curb approach here: http://help.arcgis.com/en/arcgisdesktop/10.0/help/index.html#/Route_analysis/004700000045000000/ Jay Sandhu ... View more

Is there no tool which can work with network distances (e.g. from an OD-Cost Matrix) instead of direct distances? The partitioning tools do not use distance at all! And thus cannot be enhanced by network distances. It is based on a space-filling Peano curve. Can you now me if it can at least solve my kind of problem? Than I would get into getting it to work. The Allocation tools work for the case when the facility locations are known (for example existing school locations) and they have a capacity and there is a list of demand points (e.g., school going children) that need to be "allocated" to these existing locations honoring their capacity. These scripts will not tell you where to locate your facilities. The only tool that will tell you where to place the facilities is Location-Allocation and in version 10 it does not have the capability to honor capacity. That has been added in 10.1 pre-release which will be out shortly. You can look at location-allocation literature and see how to formulate it as a Linear Programming problem and then use the Allocation tool approach to solve it by computing the OD in ArcGIS, exporting the OD out to the LP package. But be warned that this approach will take time to develop/test and it will only solve small problems and may take a long time solving to give a good solution. Jay Sandhu ... View more

If you simply want a solution then take a look at the partitioning tools: http://resources.arcgis.com/gallery/file/Geoprocessing-Model-and-Script-Tool-Gallery/details?entryID=6057ADFA-1422-2418-A056-8D337B093947 Keep in mind that this does not use network analyst or location-allocation. But will give you a specified number of clusters of a certain size. Jay Sandhu ... View more

Do note that that Location-Allocation is not trying to balance all choosen facilities with the same amount of demand, so each facility can have a wide range of demand points assigned to it. However, you should not get two different solutions on the same data/problem on two different machines. If you are geting different behavior then it could be a difference in the underlying network dataset (restrictions, impedance, etc) or the locations are not correct. By that I mean you may have loaded the locations using "network locations" instead of geometry when in fact the network locations have become stale. You could create a new Location-Allocation layer on your problem layer, re-load the locations making sure to check on the Use Geometry and not the Use Network Location Fields and re-solve. If this does not solve the issue, then perhaps you can post a screen-shot of what you are getting. Jay Sandhu ... View more

After dissolve network, you need to Build Network. Else it will say 0 features as the network has not been built yet. And yes, it can reduce the number of features by half. Jay Sandhu ... View more

Building a large network dataset can take some time. You can go to the %TEMP% folder and see the contents of the BUILD.TXT file to see what progress is being made by the build. A version of the streetmap is available free with ArcGIS. It is on the data and maps dvd. It already has the network dataset built for it. There is no need to extract the streets and create a network on the subset. It is also available online. Perhaps you have already downloaded it. You can search the forums for other posts on people setting it up, for example: http://forums.arcgis.com/threads/15722-ESRI-StreetMap-network-dataset-error?highlight=streetmap+download As far as the lengths being small, the streetmap data is in decimal degrees and that is why you see small lengths. If you use the network dataset wizard to create the network, do not add any attribute and when you go "next" it should say that it will add a length attribute based on the correct length in meters. Jay Sandhu ... View more

Can route capacity (Gross Vehicle Weight) be accomodated by ArcLogistics when determining "optimal" routes? Yes. See the note on "Capacities" where it talks about Route properties. http://help.arcgis.com/en/arcgisdesktop/10.0/help/index.html#/Vehicle_routing_problem_analysis/00470000004v000000/ Jay Sandhu ... View more

Is the turn feature class part of the network dataset? Did you assign any attribute value (restriction) for these turns? Can you see the turns draw in ArcMap when you add the network dataset? If you can see them, use the network identify tool (second icon from right on the NA toolbar) to click on turn feature class. Check the values associated with the turns? Do they look right? Is the connectivity to the edges correct? Jay Sandhu ... View more

After creating the Network Dataset, did you Build it? If not sure, then bring up the properties of the network dataset and in the General Tab it will list the status of being Built or not Built. In ArcMap, the things needed to make the menus active are: Make sure the extension is turned on (in ArcMap via Customize drop down menu) Add the Network dataset to ArcMap TOC (can you draw it?) Jay Sandhu ... View more

You appear to be doing things correctly. That is, attribute selection on RTE and then spatial selection where the target is the rte_ND_Junctions and the source is the RTE with the "use selected features". Make sure you clear selection before you start. After the spatial selection, OPEN the rte_ND_Junctions attribute table and see what selections are on it. That is, the result of selecting from target rte_ND_Junctions HAS to be in the rte_ND_Junctions attribute table. It CANNOT be polyline as it is a POINT feature class. Jay Sandhu ... View more

You can use the Route Solver with the ROUTENAME property to solve paths between many pairs of stops with the same "routename". You can read more on ROUTENAME here: http://help.arcgis.com/en/arcgisdesktop/10.0/help/index.html#/Route_analysis/004700000045000000/ The trick will be to set up the data properly. You can load your 4,371 member points with a unique ID for the route name property. Next you need to load the corresponding 368 locations with the same unique ID. That is, you have to load these as 4,371 points, where your 368 locations are repeating. You could do this with some relates... You can search these forums for ROUTENAME for more info. Jay Sandhu ... View more