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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8
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0answers
168 views

Can GRASS compute the line graph representation of an input graph?

I'm interested in computing a line graph for an input graph, preferably in GRASS since I'll be using other GRASS network analysis tools afterwards. I couldn't find any reference to line graphs in the ...
5
votes
0answers
788 views

How to use Route Task in Network analysis tools

I am using esri network analysis tool and I just want to draw the path between two clicked point on the map (by using route task) I use the example code block in the following link ...
4
votes
0answers
26 views

“Merging” 2 layers of LineString with splits at intersections

I would like to "merge" 2 networks of lines and these lines need to be split when they intersect. With pictures it should be clearer : What to do: if a black line intersects a red line, they ...
3
votes
0answers
37 views

Calculating a specific distance from points along a network - GRASS

I'm currently using the v.net.iso function in GRASS (no access to network analyst in ArcMap). Does anybody know of a way to export the result to shapefile so that you have an individual line ...
3
votes
0answers
67 views

How are costs returned by the pyQGIS implementation of Dijkstra calculated?

How are the costs returned by pyQGIS implementation of Dijkstra (QgsGraphAnalyzer.dijkstra) calculated? As far as I know, these costs correspond to the distance from the starting node to each of the ...
3
votes
0answers
111 views

Steiner tree problem: Optimal routes for Fibre planning on road network

I am trying to solve a large optimization problem where I have a set of nodes on a road network that need to be connected using fibre using the shortest possible amount of fibre. The problem is a ...
3
votes
0answers
177 views

Is it possible to create Isochrones in QGIS GUI?

I'm new to QGIS and have tried to create isochrones around points for quite some time. Is there any option to create isochrones on the GUI in QGIS? I know how to create them using pgAdmin (using eg ...
3
votes
0answers
82 views

How to find the minimum number of inspection points?

I am working on a pipeline inspection project and there is a high liklihood that some inspection tool deployment/retrival station will need to be installed on the pipe network. the problem is ...
3
votes
0answers
167 views

Three Dimensional Routing Input Location Errors and Questions, ArcGIS10

I am having a bit of a problem with my three dimensional route solving. I am creating an interior building network, and ideally would be routing from room to room. I created a line feature class, with ...
2
votes
0answers
23 views

QGIS Broken Link to files on a server

My colleagues and I are using different versions of QGIS (2.8.2, 2.86 & 2.14) on windows 8.1 and Windows 10. When we open existing projects we get a "Handle Bad Layers" box coming up. We have ...
2
votes
0answers
63 views

Global shipping network datasets for download?

Does anyone know if global shipping routes for free download (preferably ESRI shapefile) exist? I would need them for my research only as a background presentation on the world image. They can be ...
2
votes
0answers
32 views

Create network graph from contiguous polygons in KML, or PostGIS?

I am using Postgres 9.5 and PostGIS. I have a table with a geometry field. This table has about 200 rows, in each of which the geometry field contains a Polygon. I would now like to derive an ...
2
votes
0answers
57 views

How to calculate shortest path from points in one layer to points in another layer via roads, in QGIS

I'm a new user of QGIS (and have experience using ArcGIS but zero programming skills) and I'm looking for a way to calculate the shortest path from addresses to subway stations via a network of roads. ...
2
votes
0answers
105 views

Finding number of left and right turns for each shortest route

I have a network dataset for a city. I have, lets say, 200 trips that are made in that city. I constructed the shortest route for the every pair of the trips, and also the actual route travelled by ...
2
votes
0answers
126 views

How to build a GRASS network with node IDs from the line dataset?

I have a dataset of street network links (line geometries). Each network link has a link id, start node id, and end node id attribute. I want to use this network in GRASS, so after importing the ...
2
votes
0answers
78 views

inputing road network as nodes and arcs in java

I want to input a road network as nodes and arcs. Some of the nodes are intersections, others serve to describe the shape of the road. Road network should be modeled as an embedded graph consisting of ...
2
votes
0answers
66 views

How to import and display a road network in XML to ArcGis?

I am trying to convert xml data to shapefile features using ArcGis 10.1. Im using the open source SUMO traffic simulation software. Part of the model process is to convert OpenStreetMap road network ...
2
votes
0answers
27 views

Path on network returning wrong results

I have created a shapefile of polylines that represent a path with multiple intersections. Then I have used the networkx python library to create a network. At the first the results were satisfactory. ...
2
votes
0answers
27 views

Route Analyst acts odd at using custom impedance

I need to do a route analysis with a custom made impedance, which is impedance based on the surface type. Here is the problem: while the route Analysis acts perfectly fine with the default cost ...
2
votes
0answers
31 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. ...
2
votes
0answers
592 views

How to specify cost attributes for network analysis in QGIS using the GRASS plugin?

I have a road dataset with information about the length, speed and drivetime for each segment. I use QGIS 1.9 with the GRASS plugin to do different types of network analysis, but how do I set up the ...
2
votes
0answers
177 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 ...
1
vote
0answers
7 views

Automating the Road Graph “shortest path” plugin in QGIS to batch compute routes

Is anyone aware of how to automate the Road Graph "Shortest Path" plugin in QGIS, calculating multiple routes from multiple origins to multiple destinations, using two point files and road network, ...
1
vote
0answers
29 views

Looking for an algorithm to quickly find the closest point on a road network (or other graph)

I am looking for a fast algorithm that will find the closest point on a line segment in a graph (such as a road network) to my test point. I'll try to be more specific. I have a road network graph. ...
1
vote
0answers
17 views

Qgis network prepare road graph

I have been working on finding shortest path between two buildings. For that purpose i have created kml files of various streets, converted them into shape files and then merged all of them together. ...
1
vote
0answers
33 views

Calculate shortest paths for each output area in catchment through road network to a single point (i.e. store)

The title sums it up pretty much. I'm looking to derive trip distributions to a single store using population data and distance within a prescribed distance catchment. I have calculated the catchment ...
1
vote
0answers
16 views

QGIS-streets network: How to get the points equistant at a certain distance from one point given?

Into a network of streets (let’s suppose polilines or polygons): How to get the points equistant at a certain distance from one point given? I know how to do this with ArcGIS with Network Analyst ...
1
vote
0answers
18 views

Nominatim installation - network flood

I've tried to install Nominatim with a planet.pnf file to a server which is hosted at Dacentec(36gb ram, 16 threads, 1x2TB 7200 RPM hard). The installation was going well, it was already indexing data ...
1
vote
0answers
21 views

Convert a polygon grid into an edge table

I'm working on a robotics project. I've got a rectangular grid (polygon shape file) that is a navigateable/routable region (i.e. I can travel anywhere in this grid). That is I took my bounding area ...
1
vote
0answers
24 views

Build network based on shortest distance between points

Is there a way to build a network based on the shortest distances between each point of a point layer. I have occurrence data from species (as points) and want to estimate whether there are one or ...
1
vote
0answers
35 views

Geoserver VM with NAS, Should I store entire VHD on the NAS or just map the data directory? Or just go with internal SSDs w/ weekly backups?

Our humble geoserver instance needs to be able to host GEOTIFF image pyramids ranging in size from a few gigs to a few TBs. A NAS appliance with raid 10 seems smart from a maintenance/expandability ...
1
vote
0answers
37 views

Adding multiple values restriction field for service area analysis using ArcGIS Network Analyst?

I have a network dataset created and I am trying to run a service area analysis for pedestrians/cyclists movements. The network is comprehensive of pedestrian paths, cycle lanes and roads as well, so ...
1
vote
0answers
37 views

Network analysis library - example from PYQGIS developer cookbook does not work

I am using QGIS 2.6. I'd like to be able to calculate the driving distance between any two geocoded locations (can't use the shortest path roads plugin because it appears to be interactive and I need ...
1
vote
0answers
56 views

How to modify the “Network Analysis Library” in QGIS?

I want to modify the network analysis library because th graph builder does something I don't want. When there is an intersection between to lines, it creates a node in it. I want to avoid this ...
1
vote
0answers
77 views

Matching vertices in igraph (R)

This is my first question so apologies if it's poorly explained... I'm currently using a combination of ArcMap 10.2 and igraph in R to analyse a network with associated data. I have an igraph ...
1
vote
0answers
76 views

Computational Geometry Problem

I have following datasets- Road network (line) Waterbodies data (polygon) School locations (point) Suberb boundaries (polygon) Property boundary -buildings (polygon) What i want- Generation of ...
1
vote
0answers
230 views

Removing pseudo-nodes using QGIS Sextante plugin?

I have a road network (vector) that i'm interested in carrying out some space syntax analysis on. Predictably my GIS data is in a pretty terrible state. For example, there are a bunch of roads on the ...
1
vote
0answers
121 views

What is the reason for the very poor performance of ESRI's file geodatabases on network drives?

I am asking this question because I am at a loss and dont have a good enough understanding of all the underlying operations going on 'under the hood' of Windows/Arcgis. What is the root cause of ...
1
vote
0answers
33 views

An algorithm that could find a random cycle in a graph

I am looking for an algorithm that could find a random cycle in a graph from a node while that cycle is traversing around another nodes (area). For example, from the green star on the left of the ...
1
vote
0answers
183 views

Representation of road networks at junctions when line width is varying with attribute

I have a road network and for every road segment the average number of daily traffic. I need to draw a map where the line width for each road segment is proportional to the daily traffic. I can do ...
1
vote
0answers
70 views

GRASS GIS: Network analysis doesn't work correctly

I got a problem with the Network Analysis function v.net.iso in GRASS. I tried it so many times but the function doesn't work correctly. I tried to calculate isolines via the function v.net.iso, based ...
1
vote
0answers
17 views

Route From Network Analyst Not Fully Displayed

I am working on a project for finding the optimized route solid waste pickup within a defined neighborhood. These are my setting for route properties. The curb approach must always be on the right ...
1
vote
0answers
72 views

how to use line feature as stops input in network analyst?

I'm trying to build a certain route with network analyst on a Network Dataset. As an input to create the route I want to use line features. I am trying to do this with network analyst in ArcGIS 10.0 ...
1
vote
0answers
76 views

pgRouting with TomTom multiNet

I would like to use TomTom multiNet data with pgRouting to create drive time/distance polygons. I have gone through the documentation regarding network topology creation, but am still confused to ...
1
vote
0answers
239 views

Asset point IDs, pipeline and flow direction

I have a data set of a sewage pipe network and point data (assets). I would like to: first calculate the flow direction of pipes (polyline feature) assign IDs to the pipelines using asset IDs ...
1
vote
0answers
65 views

How does Address Locator pick one of two alternative points in ArcGIS for Desktop?

I have geo coded the main entrance of buildings on my map and some buildings have more than one entrance. How does address locator pick one of them? To me it seems it is just randomly picking one of ...
1
vote
0answers
79 views

Determining uppermost point in stream based on gradients?

I am trying something new and was hoping someone out there may have done this same process or something similar or may have a best approach. For this particular project I am working with ArcMap ...
1
vote
0answers
134 views

network based interpolation methods, which one could I use?

I need to interpolate traffic data consisting in raw number of vehicles passing across certain points, where counters are. It is evident I haven't a uniform distribution of points and values about ...
1
vote
0answers
35 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 ...
1
vote
0answers
151 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 ...