An interconnected set of points and lines that represent possible routes from one location to another, OR in computing, a group of computers connected in order to share software, data, and peripheral devices, as in a local or wide area network.
0
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1answer
45 views
How to find the watershed area for each point in the river network？
As title, I want to find the watershed area, but using QGIS.
I have following files to work with：
stream network shapefile(polyline)
point shapefile clipped from the polyline shapefile
I want to ...
0
votes
0answers
24 views
GRASS - Creating an Attribute Based on Driving Distance
Is it possible to calculate the driving distance for each node of one layer (fire stations) to each node of another (address points)? After doing so, I need to sort all of the distances from shortest ...
1
vote
0answers
48 views
Map Matching? (Finding Nearest Roads…)
I am making Pedestrian Navigation System for my school
I created node and arc and digitized buildings with ArcGIS. Then, exported KML to use Javascript Dijkstra's Algorithm to find route.
So far, so ...
4
votes
1answer
49 views
How to find the Closest Facility (euclidean distance)?
I have some facilities and incidents, and I want to find the closest facility for each incident. I've done it via Network Analyst (with a network dataset) but I'm wondering if you can do it with just ...
1
vote
1answer
56 views
Basic traffic volume map [duplicate]
I'm trying to map the volume of people traveling from various cities to popular mountain towns in British Columbia. I have a .csv containing the starting point, ending point and number of travelers. ...
1
vote
1answer
30 views
Merge Multipart Feature Line
I'd try to merge multipart feature line, but didn't work.
would you please teach me how to merge multipart feature line?
I work in version environmental and geometry network.
Regards,
0
votes
0answers
27 views
generate hydro network topology on a stream network
I want to generate hydro network topology on a stream network without calculating catchments and drainage points.
My initial data are a Line layer (river network) and a DEM10 and the target is to ...
7
votes
3answers
200 views
Howto setup and use a remote GIS workstation (QGIS,GRASS,PostGIS)?
I'm using QGIS (and sometimes GRASS and PostGIS) on my 2009 MacBookPro for my thesis project.
I was wondering (during an endless batch generalizing in QGIS) if I can set up a server so I can work from ...
2
votes
1answer
28 views
Clipping a buffer from network analyst shapefile to a base shapefile
I have exported my polygon shapefile which I got after I ran my Network Analyst into a shapefile. It has 6 buffer zones (delimited by time in increments of 10 minutes). When I check the attribute ...
2
votes
1answer
38 views
Help with GRASS V.Net.Path
GRASS has extensive and brilliant documentation, but I still have a bit of trouble using v.net.path. in the example for shortest path, it says: "
#Shortest path: ID as first number, then cat1 and ...
2
votes
0answers
52 views
How to join nodes to network lines ( and not the other points)
I'm trying to do a shortest path analysis on my network. In order to prepare the network and attach polygon centroids to the roads, I used GRASS' V.NET operation=connect. the problem with this ...
2
votes
2answers
81 views
How to route railcars along railroads?
I'm very new to the world of GIS, but I'm learning a great deal from this site, as well as others. I fell like this should be 'easy' but I need to be pointed in the right direction. I'm trying to ...
2
votes
1answer
58 views
Finding Network overshoots under a certain distance
we have a large contiguous network that will have legitimate overshoots (like a dead end street), but may or may not have illegitimate overshoots. Using FME, I can't seem to manufacture a way to find ...
2
votes
2answers
42 views
How do I create a network from connected links
I have a bundle of links in 'some' networks. I need to find out which ones are connected to each other i.e. I need to find out which links are not connected to the 'main' network.
I have been working ...
5
votes
1answer
223 views
How to automatically create all possible polyline routes connecting many point locations around a polygon obstruction?
Lets say I have 30 ports on the west of an island, and 30 on the east, and need to calculate all possible shipping distances between each and every port, with the routes having to steer around the ...
1
vote
1answer
72 views
ArcGIS 10.1 Network Analysis- How do I get appropriate network dataset?
I have acquired London road dataset from the Open Street Map however after creating and building the network dataset in ArcCatalogue the solve tool could not return the routes because of errors no ...
3
votes
1answer
201 views
How to get the distances (shortest path) between all pairs of points in the river network?
I have 2 vector shapefiles (one line, one point), and I have tried at least 4 ways to try to get the distance matrix at one time (and most concern the directions of each river segment)
quantum ...
1
vote
1answer
124 views
How to create routable network by pgrouting with assign_vertex_id?
I'm trying to create the routable network as per http://underdark.wordpress.com/2011/02/07/a-beginners-guide-to-pgrouting/and use assign_vertex_id. Do I still need to create the node table? How would ...
0
votes
1answer
52 views
Geoportal to harvest services hosted by Geoserver
I am trying to set up Geoportal to harvest services hosted by Geoserver. I tried follow this instructions:
Open your Geoportal Server.
Go to the Administration tab Choose the 'Add' option
Choose ...
0
votes
1answer
158 views
Creating routable network table in PostGIS
I am trying to create the routable network table, as per http://underdark.wordpress.com/2011/02/07/a-beginners-guide-to-pgrouting/. Everytime I do it in PostGIS extension, QGIS crashes. The area is no ...
1
vote
0answers
38 views
Stopping the automatic snap to locator in Arcgis 10.0 reverse geocode
I built a network application using arcgis 10.0 sdk for wpf. The application uses a locator of highway milestones to reverse geocode (and identify) the "flag" the user clicked on the map.
My Problem ...
0
votes
1answer
33 views
GRASS: Loss of data using v.net
I'm trying to build a network in GRASS in order to find the shortest path from any settlement out of 1120 (points), to one waste treatment facility out of 27 (points). I plan to use v.net.distance ...
1
vote
2answers
60 views
Error using Grass v.net
I'm trying to connect my network to a points layer with a threshold of 4500 meters. I have about 11000 or so entries in my polyline and about 24 in my points layer.
I have alreday used v.distance, ...
4
votes
4answers
191 views
How to Find Dead-ends in a Road Network
I'm trying to remove all the dead-end roads in a road dataset (lines) that are less than 100m long.
How do I identify roads that are dead-ends (no exit)? The 100m part is easy. I know how to use Arc ...
7
votes
1answer
158 views
Conflating Two Network Datasets in ArcGIS
I am looking to merge two network datasets in ArcGIS 10.0. I have an ArcInfo license and have trawled this forum but am looking for some clarification. I want to merge two road networks but only make ...
3
votes
2answers
134 views
Get the junction id for the roads in a network dataset
I have a network dataset with roads and junctions. I am wondering what class I can use in arcpy to extract FromJunctionId and the ToJunctionId for each road segment in the network dataset.
Thanks.
2
votes
0answers
75 views
Plot the Shortest Paths in a Grid without any clash at a point of time
The efficient algorithm needs to be done and proved for the best solution for the given problem:
User inputs: (#) Size of the NxN Grid. (N); (#) No. of Paths: Z; (#) Source and Destination ...
0
votes
0answers
33 views
Creating transfer edges for a multimodal network
I am trying to create transfer edges for a network and what I have done is used the near tool to get XY coordinates for the closest rail segment, and repeated for the closest road segment to each of ...
3
votes
2answers
79 views
Using the ArcGIS Local Routing Tool . . geoprocessing in the runtime
When I create a model in ArcGIS using the Network Analyst Tools, I am able to create Locations and make the Route Layer and Solve. However, I need to be able to add barriers as well as locations, ...
6
votes
2answers
121 views
How can I turn a vector layer into a graph G = (V, E)?
I have a number of rail networks, in the form of shapefiles of the "line" type. I want to turn them into a more abstract graph format, i.e. the kind with vertices and edges, not chart-type graphs. ...
2
votes
3answers
79 views
Render a map showing lots of individual traces/routes simultaneously
Google's "My places" is great for showing lots of traces (in my case, paths representing bike rides I've done). But it only shows 20 or so per page.
I'd really like a map (a statically rendered .png ...
6
votes
2answers
390 views
How to calculate Network Service Areas in QGIS?
Is there any way in QGIS to apply service area buffers e.g if I have a point on a map I wish to show the service coverage of 1 mile, 2 mile, 3 mile, breaks using the road network?
3
votes
1answer
63 views
How to create a multimodal network?
How to add waterways and railroads without turn restrictions into the previously created street network dataset with turn restrictions, in order to create a multimodal network?
For a university ...
8
votes
1answer
91 views
How to create a branch network from several input points to an unique outlet in minimizing the distances?
I am searching a way to "hydrologically" connect upstream points to a unique downstream outlet by creating an optimized stream network as pictured below...
The cummulated lenght of the stream lines ...
6
votes
3answers
585 views
Find a proper path between two nodes in a grid
This question is about finding a proper path (route) between two nodes (P,Q) in a grid (i.e., graph, network, ...). In our concept, we define a path proper (nice) if it is the most similar* to the ...
1
vote
1answer
149 views
Retrieving XY from point graphics set in WPF network (arcgis 10.0)
I have a WPF application using ArcGIS 10. In the application I can set two point by clicking on map and calculate route between them. every time I click on the map, The application creates a ...
2
votes
1answer
109 views
Visualizing KMZ network link in QGIS
Is it possible to open and visualize and kmz network link in QGIS.
If so what are the setps involved?
Thanks in advance
Cheers
1
vote
2answers
186 views
Network distance computations using GRASS
I'm an ArcGIS user who's interested in learning to use GRASS. Can anyone point out resources that will help me in learning how to obtain network distances between (1) residential locations (points) ...
0
votes
1answer
117 views
PostGIS Implementation of Brabyn and Skelly Road Network Travel Time Model
Is there a PostGIS implementation of the Brabyn and Skelly road network travel time model for the New Zealand road network? This model is outlined in:
Brabyn L, Skelly C. Modeling population access ...
4
votes
1answer
399 views
Using QGIS calculate distance of point along a line
I have lots of points, and a road (lines) and I would like to calculate from point A to point B (the distance must route through the roads (lines).
I found this QGIS calculate distance of point along ...
4
votes
3answers
369 views
How to find the watershed for each outlet point and sum values within it?
I have the following files to work with:
Stream network of a basin;
Outlet points for each segment* of the network and
Points which represent water withdrawals along of the stream, which are not ...
4
votes
1answer
114 views
How do you define rail network branch geocodes
As per the attached document I'm trying to define a rail network by providing geocodes for each rail stop, how would I define a 'stop' as a junction for a branch in the network without having to ...
6
votes
1answer
225 views
calculate slope for a road network
I am working on a road network for routing operations using postgis and QGIS.
I am new to both of these tools and need to calculate the slope for each edge (by retrieving the Z value for the start ...
1
vote
1answer
259 views
Create a Minimum Spanning Tree based on a street network (ArcView)
I hope you can help me with my network analyse problem (ArcGIS 10.0 SP2 - ArcView License)
Background:
I try to create a network of fiber optic cables to specific points along a street network.
...
8
votes
2answers
264 views
Generate near table for x number of neighbours using arcpy
There are 3 likely scenerios that I am trying to capture near distances for:
An interchange subway station, which has 2 or more neighboring stations. That is, the station in question connects 2 or ...
0
votes
2answers
136 views
how to build a routeable network for pgRouting with srid 3785
I'm following the pgrouting-workshop http://workshop.pgrouting.org/chapters/topology.html and It works, but in my project I'm working with the mercator projection(srid 3785) and there is not a routed ...
-2
votes
2answers
275 views
What are non-commercial sources of road network other than OSM
I want to get the graph (Road Network) of Area of interest:
Lon/Lat - Left/Bottom = -93.28587,44.9674 and Right/Top=-93.25351,44.9855
Minneapolis, MN
Searching for a non-commercial source - aside ...
1
vote
1answer
364 views
Create closest point on multilinestring to use in shortest_path()
I am working a routing based application where I need to create a route between two points of interest. The problem which I am facing occurs after calculating network topology using ...
6
votes
5answers
717 views
How can I map a matrix of origins and destinations in QGIS?
I have a central point on a map, and I have other points in a separate layer (the location of a venue, and the origin cities of the venue visitors). Is there a plugin which would generate output ...
15
votes
1answer
195 views
Are there any standards or common practices for performing a network analysis for emergency response?
I am working on a project using Network Analyst to determine official emergency response zones for fire departments. The shape of each zone will be determined by the network (at least 1 department ...
