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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20 views

Any standards for urban rainwater drainage network?

I am starting to work on a project related to urban drainage networks. Are there any standards out there to represent this kind of network? Relevant attributes would be things like pipe section, pipe ...
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25 views

Live GPS tracking with both ping script

That's a professional context : During a travel between two train station, I would like to use the live tracking and analyse the network performance (access by Wifi & 3G/4G ). I would like to ...
3
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0answers
77 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 ...
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0answers
38 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 ...
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2answers
2k views

Selecting only canals that are connected to reservoirs?

I have a polygon layer of water reservoirs and a polyline layer of canals. In my data, some canals are originating from reservoirs, and leading to other canals. On the other hand there are some ...
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3answers
1k views

How to create an OD road distance matrix in QGIS?

I'm looking for the steps required to produce an origin-destination (OD) cost matrix. What I'm looking for is a matrix of road distances. The distance matrix tool only produces euclidian distances. ...
4
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2answers
189 views

Road segments reconstruction from GPS trajectories

We have a 10,000 base of vehicle mounted moving devices which report their GPS position on a time based schedule. All that data is currently being stored in our database for several business related ...
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3answers
256 views

Creating a simulation of how people moving around a site

I am working on a project aiming to create a geographic simulation for how people interact around a site. Situation: There are x people in an enclosed area (such as a zoo). There are y locations to ...
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1answer
43 views

Get upstream sections of a network

Is there any extension to get all upstream sections of a polyline shapefile which represent an hydrographic network in QGIS? It could work like this: you choose a specific branch and a direction ...
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1answer
44 views

Navigating a road network and avoiding u-turns

I've implemented a node-based A* search of a road network graph. I would like to penalize u-turns a places where bi-directional streets join together again, which I identify successfully via a match ...
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1answer
80 views

Reproducing GRASS GIS network analysis tutorial in QGIS Field Calculator

Im looking to reproduce the assigning of road speeds as denoted in a GRASS GIS tutorial (v.net.alloc tutorial), where the road speed is assigned by road type (i.e. 'interstate' = 75 mph etc.) to then ...
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28 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 ...
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18 views

Nested Set Model for Spatial Data?

How can I create a nested set model for a spatial line dataset? The nested set model is a technique for respresenting hirarchies of a tree (see https://en.wikipedia.org/wiki/Nested_set_model). If ...
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1answer
67 views

ArcGIS Online Network Service

Where does ArcGIS Online Network Service source came from? Is there any source reference I can refer to? I tried to search on Google but I could not find anything.
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0answers
59 views

How to find NetworkAnalysis extension with ArcObjects?

I'm using ArcGIS 10.0 My code: IAoInitialize init = new AoInitializeClass(); var a= init.IsExtensionCodeAvailable(esriLicenseProductCode.esriLicenseProductCodeEngine,esriLicenseExtensionCode....
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0answers
70 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. ...
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0answers
18 views

How do I add a fixed cost for switching modes in network analyst? [duplicate]

I am constructing a multi-modal transportation network using Network Analysis in ArcGIS. I have data on roads, railway, and rivers. My goal is to calculate an Origin-Destination matrix of the cost to ...
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0answers
39 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 ...
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1answer
75 views

Can you create a square OD Cost Matrix with Network Analyst?

I have a feature dataset and want to find the cost of travel between each pair of features. Because I'm looking for road (not Euclidean) distances, I was told that the OD Cost Matrix solver in Network ...
2
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1answer
54 views

Network generation algorithm

I am trying to solve a network generation problem, and I'd be happy about inputs. First of all, my problem description: I have a list of connections between locations with respective distances. For ...
3
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1answer
246 views

Calculating shortest paths from all points in one layer to any points in another via road layer in QGIS?

I'm trying to calculate the shortest paths from all the points in a layer representing population settlements (the green points) to any of the points in another layer representing the hospitals (...
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0answers
45 views

Water main Flushing

I am trying to make a basic network on which I can derive some watermain flushing routes (similar to the software InfoWater UDF). Watermain flushing depends on closing specific valves to direct water ...
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1answer
35 views

Does ArcGIS Online include High Speed Rail in its network analysis?

I'd like to run an OD Matrix using network analyst in Europe and Asia to study high speed rail. Does ArcGIS online include HSR (such as the AVE in Spain or the TGV in France) in its analysis?
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2answers
272 views

Can ArcHydro tools be used on a network in an SDE enterprise geodatabase?

Most of the documentation for ArcHydro tools discusses their use on data in ESRI's personal and file geodatabases. Is it possible to use ArcHydro tools to set network flow direction on a networked ...
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3answers
182 views

Filtering polyline features by direction using ArcGIS 10.2 (or ArcPy)

I have a polyline shapefile depicting a real road network. In many parts it has two 100 % overlapping segments in opposite directions, representing the two driving directions (In picture: red segments)...
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1answer
96 views

Update values from layer one to layer two where there is no identical ID but identical geometry

I have one huge problem and that is to get the value from one layer into another. It is a network with over a million links and I need to update a table from a layer of + 100 000 links. I am using ...
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2answers
3k views

Segment road network line shapefile into new equal length segments line shapefile?

I would like to subdivide a road network for an entire state into segments of equal length. So, Highway X would be divided into 0.5 mile segments, with a record for each segment, and Highway Y would ...
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0answers
104 views

Error when stop editing a feature in ArcPy [closed]

I want to make changes in a feature attribute table that is an edge source of a Network dataset. In the next step, I need to rebuild the Network to make the changes take efect. The problem is that, ...
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0answers
800 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 http://help....
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8answers
5k views

Representation of network flows

This is a sample transportation network flow I've done a year ago based on 26 zones. For a project I'm working on now, I need to represent the flows over 1,000 zones with directionality. Any ...
3
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1answer
41 views

Distinguishing Road Network according to the ward within a municipality ArcGIS

I have a polygon layer of a municipality containing 14 wards as shown in figure i. I also have a polyline layer of road network irrespective of the ward. The road network have following attributes -...
2
votes
1answer
130 views

pgrouting calculate length of shortest travel time route

I currently use the pgr_kdijkstraCost() function to calculate the travel times of a few origins and destinations. But I would also like to return the distance length of these trips. Is this possible? ...
2
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1answer
77 views

Adding elevation data to a network dataset

I am trying to add elevation data to my road network to more accurately calculate walking distance to and from schools. I have figured out how to do the network with out elevation, but for the life of ...
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2answers
78 views

Distance between two points in a line feature

I have two layers, one with lines and the other with points. Layer one has all the points (A to J) as shown below and layer two has all the lines connecting these points. Is there an automated way (in ...
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0answers
45 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 ...
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0answers
35 views

How to create a mean centre using a network dataset

I have a set of offices, with the number of workers in each office. I need to find the mean centre of these offices weighted by the number of staff. E.g. the 'centre of gravity for staff.' I have done ...
2
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1answer
95 views

Image cache on network drive vs. SDE/Oracle

We currently have all of our image data loaded into ArcGIS SDE/Oracle 9.3. There is a proposal to not load our 2015 orthoimagery into SDE/Oracle in order to save time and place it in a tile cache or ...
2
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1answer
60 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 ...
7
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1answer
198 views

Visualizing road Intersections & connections in ArcGIS

I am working with polylines (roads) in ArcGIS and I was wondering if there is a possibility to somehow show intersections as well as connecting parts of all the different road-segments. Also, would ...
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0answers
71 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 ...
4
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1answer
4k 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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0answers
93 views

Why does cascaded WMS not work? (Geoserver)

I run a Geoserver installment as a service on a Windows Server 2008 R2 machine. I try to add a WMS source but everytime I get timeout-exception. As I need to use a proxy I edited wrapper.conf as ...
5
votes
2answers
951 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 ...
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0answers
77 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
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1answer
67 views

PgRouting: Target vertex error

I'm trying to make a matrix that shows the cost from a node to the rest of the nodes in a network. The final result I'm looking for is not the cost, but only know if a car can or can not reach each ...
0
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1answer
84 views

Calculate distance between two coordinates along lines

I have a map with two layers: a map of the streets of Montevideo, and a map of shops with the lat long location. I would like to calculate the distance between each shop and the nearest one, along the ...
1
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1answer
222 views

Geometric Network Find Upstream

I am New to Geometric Networks. I need to build a river network and find all locations (polygons) upstream. This is the template I am trying to use. I have my rivers with to and from node and the ...
0
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1answer
109 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. ...
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0answers
43 views

How to reconstruct a network with multipart edges to a network with singlepart edges

I have a network shapefile that between its vertices , there are edges that have multiple geometric objects. When I try to node it in postgis, it creates multiple segments in the database that ...
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0answers
250 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 ...