# Tagged Questions

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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### 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 ...
56 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 ...
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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### 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 ...
264 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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### 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 ...
100 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 ...
83 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 ...
106 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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### 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.
375 views

### Creating network datasets from OSM data in QGIS?

I am having a difficulty to use network analysis in ArcGIS because of unavailable network datasets. So, I googled it and realized that it is possible by using OpenStreetMap. However I don't know how ...
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### 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 -...
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### 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? ...
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### 'D8 contributing area method' - TauDEM with QGIS

I'm using the TauDEM on Qgis to extract drainage area network from DEM. I could do it easily using the threshold method of TauDEM. Now I would like to do it using a shapefile of the inlets of the ...
82 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 ...
80 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 ...
46 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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### 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 ...
196 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)...
103 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 ...
80 views

### Mean centre on the roads network

I am trying to evaluate the current police stations. so I want to find the mean point of crime points in the city and compare the OD cost matrixes of the results. Is there any way to find the mean ...
205 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 ...
72 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 ...
97 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 ...
103 views

### Matching vertices in igraph (R)

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 network object based on the OS ITN network with associated TOIDs for each ...
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### 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 ...
231 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 v....
68 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 ...
230 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 ...
113 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. ...
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 ...
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 ...
264 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 ...
123 views

### Can DARP be used for Non Emergency Medical Transportation problems?

I have a Non-Emergency Medical Transportation (NEMT) business and am looking for the best solution that can automate the dispatching process. I looked over DARP and it seems fine. I need to know 2 ...
132 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 ...
59 views

### Best way to filter points given a starting point and max travel time

I have a database of about 1M geolocated addresses and I'm looking for a way to sort/filter these records based on a starting point and max travel time. Ex: "find every baker shop within 30 min ...
135 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 ...
406 views

### ArcGIS tool for graph analysis

I have a road network shape file. After creating Network dataset I get a graph with vertices and edges. I need to create a tool for ArcGIS (through a Python code) which enables to calculate depth of ...
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### Simple way to share maps on a network drive?

I am not an expert in web GIS and I would like to share some maps I created with non GIS aware colleagues from other offices. I have looked at various options but I can't find one that suits my needs. ...
84 views

### Using Copy Traversed Features to count turns for a route result in Network Analyst

I have the output of the route layer. And I want to determine the number of right and left turns for each route. For that, I used the COPY TRAVERSED ROUTE FEATURES tool from Network Analyst. However, ...
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### Python script to accumulate flow volumes for a pipeline geometric network

I have a point wells layer and a polyline pipeline layer. The wells are snapped to the end of the pipeline segments. The wells layer has weekly updated flow volumes and I'd like to find a way to ...
39 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 parks,...
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### 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 ...
118 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 ...
121 views

### Calculating driving distances from a number of post codes to a number of services using QGIS

I am hoping to calculate the driving distance from a large number of post codes to their nearest service. I have used the RoadGraph plugin but this only calculates the distance and time from one ...
193 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 ...
80 views

### Nearest intersections outside the polygon in ArcGIS for Desktop?

I have two layers, a street network and a polygon, and I want to find the nearest street intersection points just outside the boundary of the polygon. For example some area is closed by police and I ...
186 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 ...