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.

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86 views

Find directly joined neighbour points using a different line layer in QGIS

I have two layers of data: A set of points showing every significant point on the UK rail network (Network Rail Stanoxes). These are a mixture of stations, junctions, timing points and signals. An ...
1
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1answer
91 views

How to assign node IDs to links in a network?

I have two shapefile layers in ArcGIS for Desktop 10. I have one line layer and node layer. My node layer(shp) has a "code_1" field and line layer has a "code_node" field. The intersection point ...
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15 views

calculate distances between different components in a (cable-) network

I have to calculate all distances between every different components in a cable network (for example the distance between an amplifier and a modem) and have to show the results in a diagram (frequency ...
5
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4answers
886 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 ...
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1answer
38 views

How do you remove isolated roads from a bigger network?

I'm trying to perform an OD Cost Matrix calculation on a set of points using a road network from OpenStreetMap data. The network contains lots of roads that don't connect to the rest of the network. ...
2
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1answer
192 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 ...
3
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1answer
44 views

Split lines at intersections in PostGIS (must be simple but…)

I'm usually closer to my answer than now, but I've looked at all the answers here and couldn't adapt one to work on my data and I'm stuck. I have oriented polylines (Montreal's train network) and ...
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3answers
2k views

How to emulate Google Maps driving directions using pgRouting?

Would like to emulate google maps' driving directions functionality but use pgRouting instead. google's data over the project area & scale is quite a bit off so we want to use our own transport ...
3
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1answer
77 views

how to create a network from gps tracks?

I'm trying to build a network from several GPS-trakcs, to digitalize hiking routes on my land. I have several GPX-files from routes I've tracked with the gps. I managed to display them in Arcmap ...
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1answer
288 views

How to create a service area using both streets and buslines in the same network?

I want to create a network analysis more difficult. Therefore, I want to calculate a Service Area around hospitals next to busstops. But: The network does not only consist of roads and ...
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134 views

QGIS 2.2 problem, loading layer into road graph

I have the road graph plugin installed, but when I try to configure it with the Settings dialogue, no layer names appear in the Layers field. I have tried various shapefiles, but the Settings dialogue ...
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2answers
145 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,
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2answers
66 views

Suggest an algorithm to measure how a node is connected to road network

I try to measure how well a node is connected to the rest of the network. If a city has a distant suburb connected with one sole road, it's connectedness is, say 1. If it's connected by 2 roads, it's ...
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0answers
15 views

Why don't my service area polygons follow my network?

I have found a few similar questions, but no good answers, so here goes another Service area question: I'm working on creating a walking distance layer from Parks, and have a road network set up with ...
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0answers
24 views

What can I do in qgis to manage a WMS frequently unreachable?

In my project I have a layer linked to an external WMS server (provided by a local institution). The problem is that it is somewhat unreliable: it is down rather often. Is there something I can do to ...
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0answers
45 views

Network trace using attribute as a stop/barrier - ModelBuilder

I have two point datasets, one to be used as the flags(starting point) that i'll call dataset A and one as the barriers(stop point) that i'll call dataset B, in the trace(downstream) tool. In each of ...
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0answers
68 views

how to add polylines(routes from public transport) on postgresql(pgrouting) with GUI

After searching a several long time... i decide to ask here for help, im currently using ubuntu 12.04(because of compatibility) with postgresql 9.1, postgis2, pgrouting2 and qgis2.2 i need ...
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1answer
59 views

SpatiaLite: Creating to, from nodes from a normal road layer (LINE)

Following this tutorial but using my own data. How do I create the from_node and to_node columns? I am using Spatialite and Sqlite3. I'd prefer to not use a gui as I'm working remotely via ssh on a ...
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1answer
51 views

Alternative way to generate service area in ArcGIS - No Network Analyst License

I am working on a project currently that relates to creating service areas for points across California based on streets. I created a python script that can take a point and create a buffer around ...
4
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2answers
539 views

Does pgRouting support turn-by-turn routing? [duplicate]

I have route list as result of pgRouting with street names. How to get messages "Turn left", "Go along" etc ... Can pgRouting do this or I need some other source and which?
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0answers
18 views

problems using GRASS v.net and v.net.allpairs

I am using GRASS 6.4.3, and I am trying to use it to do network analysis. I have a line shapefile and a point shapefile, and here is my code(I take v.net.allpairs as my reference): v.net tc_bf25 ...
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0answers
9 views

problems using v.net.allpairs

I am using GRASS 6.4.3, and I am trying v.net.allpairs to do network analysis. I have a line shapefile and a point shapefile, and after I use v.net.allpairs, I type the command d.vect network, and I ...
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0answers
25 views

Topology rules for a 3d network

I am currently writing a spec to which people may end up using to guide the digitization of a large 3d network (exterior pedestrian network + building interiors). In 2d network drawing, it seems to ...
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0answers
14 views

How to add a road to a network dataset

I have a street network file, and I want to add a section of road to it. I start editing on the road network dataset, snapping on, create a new feature line road segment from the edge of the old road ...
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1answer
55 views

How does the tolerance influence QgsGraphBuilder and tieing of points?

I am developing a script which uses OpenStreetMap data to calculate the distance (over the road network) between each building and the nearest hospital. To do this, I mainly follow the official ...
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3answers
57 views

UK road network dataset

Can anybody guide me to a website or a source to download the Geographical UK road network data set. The data set should include the road distances, since I want to apply shortest path search ...
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0answers
64 views

Traversing all possible road routes

I have created a topology from OSM data and would like to simulate a car driving every possible route along the map. The purpose is to "survey" the osm data as if in a car. My ultimate objective is to ...
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1answer
45 views

Analysing a network distance to two or more points using GRASS or QGIS

I am doing a piece of analysis work looking at distances along a network in GRASS. Most of the analysis involves finding which parts of the network are within 600m of a series of points. GRASS does ...
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1answer
633 views

How to find the watershed area for each point in the river network using DEM?

Update#1: Thanks, Micha, I have followed your instruction and successfully use the modules in GRASS. I use r.watershed to get the basin raster and the drainage line: and I use r.water.outlet to get ...
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1answer
164 views

Read and Export OSM Road Data as a Network of Road Segments [Adjacency Matrices]

I wish to extract from an OSM file a road network, and export it as an array (adjacency matrix) where the nodes are the road intersections and the edges represent the road segments. I don't want to ...
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0answers
19 views

Why outside border of a service area is always not reasonable?

In ARCGIS 10.1 network analysis, why results of service area are different if number of break points is changed? For example, the grid is 300m*300m, I try to produce service area around a node. ...
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2answers
53 views

How do I create blocks from a road network?

I have a road network and for every enclosed area within the network I want to create a polygon that represents that area. How does one do this?
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1answer
33 views

How to compute drive access to a station based on vehicle origin points? [closed]

I have a shapefile that contains station locations and another shapefile that is the geocoded origins of those who drove to the station. I would like to make a buffer around the station that shows the ...
2
votes
3answers
193 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 ...
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0answers
100 views

Drawing a road network: offsetting overlapping lines (directed graph)

Say I have a road network defined by a table, indicating, for each arc, its ID, and its head and tail node. In other words, my network is defined as a directed graph. For example, we have two points, ...
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0answers
24 views

How to turn this into a routable network that works with pgRouting? [duplicate]

I'm only asking again since I didn't get any answer and I'm still stuck here... I updated my last question with more info, but it wasn't answered. When I draw a line with snapping enabled and try to ...
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1answer
42 views

How to make pgRouting understand bridges and tunnels?

I have I highway that runs on a bridge over a couple of blocks in a city. How do I get pgRouting to understand that cars can't move from the small blocks on the ground up to the highway on the bridge ...
3
votes
3answers
133 views

How to convert Midpoint of Polyline into Point Feature using ArcPy?

I am trying to write a python script to determine flow direction on a water pipe network. I've used this script to find the mid point along each polyline, now i need to convert this data into a point ...
7
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1answer
176 views

Do ModelBuilder or Geoprocessing tasks run slower if screen locked?

Is it true if you are running ModelBuilder or a geoprocessing task on a large raster\vector dataset then locking the computer would that cause the ModelBuilder or any geoprocessing to run slower? Is ...
3
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2answers
115 views

Create network from shapefile without ArcGIS?

I want to perform shortest-path analysis on a network whose edges represent real-world roads and whose nodes are buildings or other locations. I have the shapefile for the area I'm interested in. ...
0
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0answers
62 views

Network Analysis-shortest combined distance to one point

First let me confess I have little experience doing network analysis so I assume I know nothing (in essence approach me like my girlfriend does). Anyway, I am attempting to solve what I believe to be ...
6
votes
1answer
340 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
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1answer
64 views

Creating a point buffer along a road network [duplicate]

I have a road network and have added points indicating fire hall locations. How would i go about creating buffers on those points following the road line. The result am i looking for would create a ...
1
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1answer
43 views

Infrastructure networks in GIS modelling

I am currently working on a GIS-based project which aims to model the interdependency of existing infrastructure networks, e.g. transport, oil, pipeline networks, etc. The network interdependency ...
0
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1answer
264 views

How to build a Spatialite road network from OSM data

I'm looking for algorithm which could help me with building my own road network (for routing) from OSM data. I chose Spatialite DB for this, but here I have only one problem: Spatialite provides ...
0
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2answers
203 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 ...
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0answers
28 views

Time attribute problems with Network Analyst

My network dataset is in a geographic coordinate system, and when I project into UTM to calculate Miles for a length field to use with my Speed Limits to create a time attribute it does not seem to ...
3
votes
0answers
60 views

District heating expansion design with ArcGIS [closed]

I am quite new at GIS but I have some experience of the basic concepts involved in a workflow of them. What I currently want to do is to calculate the cost of expanding an existing district heating ...
5
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3answers
286 views

Tracing up a stream network & tabulating attributes of polygons it passes through

I have an ArcGIS question that is either very easy or impossible (my favorite kind). I am somewhat inexperienced when it comes to dealing with network analysis, so maybe I'm missing something major ...
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6answers
1k views

What is the best method of visualizing a network on a map?

I have several hundred geo-referenced data points, and the relationships from that point, to other points. I'm trying to figure out the best way of visualizing this on an interactive map (possibly ...