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.

learn more… | top users | synonyms

1
vote
1answer
2k views

How can I calculate driving distance between 2 lat/long points

I want to build a .NET application that can get an input of 2 lat/long points and return an output that specified the driving distance between the points. Appreciate suggestions for API's or methods ...
1
vote
1answer
17 views

How to use GRASS v.kernel to calculate point densities along a network?

In a road network, I need to select the segments where a minimum of 5 dots occur (1 dot = 1 address) over a distance of 100 m (the image attached illustrates my question). I'm trying to use GRASS ...
1
vote
1answer
40 views

Calculating Distance and Time on a network without the use of ArcGIS Network Analyst

I'm trying to calculate a distance and time for walking commuters (about 30,000 records) on a street network (NYC Lion). I have a starting and ending address for each record that have been geocoded. ...
1
vote
0answers
52 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
58 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
28 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
107 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
36 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
42 views

What is the math behind Avoid High, Medium, low in Network Analyst and can it be changed ?

When you are creating the network, in the attribute section you can define restrictions. Of such restrictions are Avoid High,Medium, Low and Prefer High, Medium, Low can someone mathematically explain ...
1
vote
0answers
21 views

Is there a QGIS equivalent to ArcGIS's Make OD Cost Matrix Layer (Network Analyst)? [duplicate]

I'm looking to create a OD cost distance matrix for a network data set I have created. Is there a way of doing this in QGIS which is akin to Make OD Cost Matrix Layer within ArcGIS's Network Analyst. ...
1
vote
1answer
116 views

QGIS 2.6 simplify a road network to obtain the intersections

In QGIS 2.6.1 in Ubuntu, I want to measure the density of block in this city (FYI my final aim is to measure the TOD level). I have the road network from French national IGN dataset BDTopo. I have ...
1
vote
0answers
13 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
50 views

Map Routing (paper route) [closed]

I am doing a undergraduate GIS project. It entails a paper route for newspapers in the Pittsburgh Area, so far I have plotted all of the points in a point layer. I have now plotted my points, what ...
1
vote
1answer
72 views

Grass GIS “v.in.ogr”: How to prevent crossing lines from beeing split where they don't share a common node?

I want to import a road network into grass gis to run network analyses. I use "v.in.ogr" to import my road shapefile. The problem is that Grass GIS seems to split every crossing line no matter if they ...
1
vote
0answers
45 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
1answer
58 views

Compute nearest points to other points using GRASS

I have a layer of address points and a layer of polling stations. My task is to determine the three closest polling stations to each address on the street network. I think that the answer is in ...
1
vote
1answer
55 views

How to assess quality of the TSP algorithm?

I'm trying to develop my own algorithm for solving Travelling Salesman Problem (TSP) I tested it (in its current state) on the "att48" instance of the TSPLIB and got following results: As we can ...
1
vote
0answers
50 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
126 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
52 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
70 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
57 views

Examples of evolving networks in GIS [closed]

I'm a master student working on networks analysis in general. A network is something that has nodes and there are links between the nodes. Nodes and links could have attributes. An evolving network is ...
1
vote
0answers
97 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
32 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
105 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 ...
1
vote
0answers
208 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 ...
1
vote
1answer
86 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 ...
1
vote
0answers
150 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 ...
1
vote
0answers
239 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, ...
1
vote
1answer
189 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
vote
0answers
47 views

Time attribute problems with Network Analyst [closed]

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 ...
1
vote
0answers
131 views

SQL procedure(s) to convert GPS traces to an ordered set of junctions in a network

I have three datasets that I have loaded into a geodatabase (spatialite or PostGIS): A set of GPS points collected from individual trips through urban areas. Points have a unique point id, a group ...
1
vote
1answer
70 views

how to extract network of city routes from city blocks shape file?

I have a shapefile which contains urban blocks. So, I am going to extract network shapefile of city routes and calculate total length of network arcs. I am using arcgis 10 for this work. Is there any ...
1
vote
0answers
59 views

Deleting network features in python script doesn't create net junctions

I have a script that makes a copy of a network dataset for a 3rd party app to use. One of the junction feature classes causes problems with the app. The ideal solution would be to remove it from the ...
1
vote
1answer
189 views

ArcView: Trim polyline, that is shorter than specific dangle length (alternative to tool: Trim Line)?

I am looking for a way to trim dangles from a polyline shape, that are shorter than a specific length like the Trim Line Tool for ArcEditor and ArcInfo, but with ArcView-License. I already discover, ...
1
vote
0answers
302 views

Calculating walking routes along a network(ArcGIS)

I've created a network consisting of footpaths, dirt tracks and junctions. I would like to calculate a route using network analysis by giving ArcMap the time and walking speed that the route should ...
1
vote
1answer
116 views

Clipping without cutting features

I want to create a multimodal network dataset for the city of Montreal. I have roads and transit lines features for Quebec province (where Montreal is). Because I need the features limited to Montreal ...
1
vote
0answers
202 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 ...
1
vote
1answer
106 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
0answers
81 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 ...
1
vote
0answers
129 views

how to set in arcgis network analysis that use every road segment max m times? [closed]

excuse me if my english ins't good. I have one incident and 120 facility. i wanna set criteria in Arcgis network analysis that if any road segment used for example m times, for other route doesn't use ...
1
vote
0answers
332 views

Open Network Dataset with ArcObjects SDK 10.0 .NET

I develop desktop standalone application and use this code to open Network Dataset, but it fails with HRESULT on datasetContainer3.get_DatasetByName(). public static ...
1
vote
1answer
106 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 ...
0
votes
2answers
245 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 ...
0
votes
2answers
249 views

Shapefile to Network xml

I have a shapefile representing the US freight highway network available from Oak Ridge National Lab. I'm trying to prepare this as a .xml network for processing with MATSim. The output structure is ...
0
votes
2answers
134 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 ...
0
votes
1answer
87 views

Adding additional nodes to network in Grass GIS

I have created a network in Grass GIS (using v.net, nodes option). I then want to "disrupt" the network (i.e., create some road blockages) and add in nodes to the new line ends where road blockages ...
0
votes
1answer
26 views

Creating network in ArcMap from an RGB image to find optimal path between locations?

I am hoping to find optimal routes from an Origin (car park) to destinations (Library, Blocks, Rec Center). I have an RGB ortho-mosiac image taken from an UAV that I want to digitize paths, car ...
0
votes
1answer
18 views

What causes v.net connect “Failed to find intersection segment” and how to fix it?

In GRASS 7, when running v.net connect, I get the ERROR: Failed to find intersection segment and no output is generated. The only mention of this error Google found is in the source of connect.c What ...
0
votes
2answers
41 views

How to calculate miles of road in street network

I have a road network we use for our city. It has ever single road created and categorized. What would I do if I wanted to calculate the total miles of roads in this network?