Questions tagged [qgis-network-analysis]
For questions about network analysis using QGIS
38 questions
2
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1
answer
68
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Routing fastest route with weighted paths in QGIS
My task is to assess pedestrian safety in urban areas by analyzing how many formal (pedestrian crossings, signal crossings etc) or informal (jaywalking/non-signal crossing) are along the shortest path ...
- 495
5
votes
2
answers
230
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Calculate network length covered by service area in QGIS
The resulting MultiLineString features of Service area (from point) and Service area (from layer) in QGIS usually contain several overlapping lines.
How can the length of the network covered by the ...
- 1,569
0
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0
answers
66
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QNEAT3 'Iso-Area as Polygons processing error
I am doing a network analysis on QGIS.
Versione di QGIS: 3.28.12-Firenze
Revisione codice QGIS: dcc633b2de
Versione di Qt: 5.15.3
Versione Python: 3.9.5
Versione di GDAL: 3.7.3
Versione di GEOS: 3.12....
- 1
2
votes
1
answer
291
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How can I merge two line layers correctly for network analysis in QGIS?
I have a graphical model in QGIS that takes a basic sidewalk network (derived from OpenStreetMap data where separate sidewalks geometry exists) and adds additional crossings automatically. As a last ...
- 1,569
2
votes
1
answer
144
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Network analysis (with slopes)
Using the QGIS network analysis (layers) command, I can calculate the maximum areas that a "bus stop" point can serve by determining a distance X.
However, I would like this distance to vary ...
- 21
1
vote
0
answers
66
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Finding lowest and second lowest values within selection, using expressions QGIS 3.24
I need to calculate the closest and second closest point in one layer, measured from points in another layer. I have used Qgis Network Analysis "OD Matrix as table from layers" which gives ...
- 81
1
vote
0
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161
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Making shortest path for number of each points with link layer in QGIS
I want to make shortest path for a number of each points with a link layer in QGIS.
Now, shortest path tool have to click the start point and end point one by one.
But I have 2,000 pairs.
So I want to ...
- 11
2
votes
1
answer
291
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Routing along existing road network using QGIS
I just started learning QGIS and PyQGIS. I have one layer of a shapefile that contains a road network (image 1) and one layer of the CSV file (image 2) that contains several start and end points for ...
- 21
1
vote
0
answers
78
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Route direction based on road width?
I have road polyline data that contains a road width field (in meters) and I want to visualize road direction, based on this road width field.
The road direction that I mean is kind of like this:
(...
- 21
2
votes
1
answer
974
views
Selection of best site for factory in QGIS
I am stuck trying to determine, where it would be preferable to locate one or more factories according to the data shown below.
The criterias for the selection of the site(s) are:
There must be 15 ...
- 31
0
votes
1
answer
709
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QNEAT3 Shortest Path works but OD Matrix doesn't
I have successfully created a shortest path layer using QNEAT3. When I try and use the OD Matrix from layers as lines (M:N) i get NULL values.
My network layer is correct (as it works for shortest ...
4
votes
1
answer
564
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QGIS Network analysis: speed for walking time, considering ascent
I'm fairly new to QGIS and I'm doing a personal historical project on some network analysis for my local area. I've got my points and my road/path network, distance matrix, etc. However I can't help ...
- 61
2
votes
0
answers
261
views
Concave Hull around Line Features
I am using QGIS 3.16.10.
I know that the Concave Hull tool is normally used with points, but I've used it successfully with line features before (k-nearest neighbor only).
I'm just trying to get ...
- 121
1
vote
0
answers
27
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How to remain or reconnect the attribute of the "from" and "to" point in network analysis
I am doing a network distance analysis from layer 1 to layer 2. I used GRASS/v.net.distance. I have one problem with the outcome is that I cannot link back the result with the original point layer.
...
- 79
6
votes
2
answers
1k
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QGIS Plugin for Shortest path with multiple Stops
I have been asked to find the shortest route from a particular start point to multiple properties along our shires road network. In QGIS I have tested the different network analysis tools and other ...
- 333
1
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0
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26
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QGIS clipping OpenStreetMap but still being able to run functions such as ORS Tools on the layer [duplicate]
I have struggled to find a solution to be able to clip an OpenStreetMap (OSM) raster layer but still run functions using plugins such as ORS Tools. I would like to clip OSM with an overlaying vector ...
2
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0
answers
131
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Calculating driving time between two layers (patients & hospitals) using QGIS
I need to calculate the driving time (following US roads) from patient coordinates to hospital coordinates. In total, I have ~ 250,000 driving time to calculate. I previously used ArcGIS but now I ...
- 21
2
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0
answers
50
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Setting restricted segments in network using QGIS
I am trying to set up a network with QGIS. When I set the direction field there are three options for the values in that field:
Forward direction
Backward direction
Both directions
but I need to set ...
- 1,079
3
votes
1
answer
393
views
Network Analysis - Service Area Tool doesn't consider all lines?
using the Service Area Tool from the Network Analysis (Toolbox) gives strange results. As you can see on the screenshot the calculated blue service area (network: streets; start points: points; path ...
- 31
0
votes
1
answer
221
views
Iterate the shortest path point to layer
I have two layers. First layer defines the starting points and the second defines the end points. I just want to iterate the same algorithm "point to layer" by considering all the points of the first ...
2
votes
0
answers
75
views
Shortest path analysis has unattainable vertices in result from PyQGIS
You can try this code directly in the console. It basically finds the shortest path but I only have unattainable vertices in the result.
Do you know how I can correct this?
My layer consists of ...
1
vote
0
answers
123
views
Creating distance radius along line network from point [duplicate]
In QGIS I'm trying to create a 1/4 mile radius (1,320 ft) around a point. I could obviously use buffer, which shows 'as the crow flies' - but I would like this along with the road network (in green). ...
- 11
1
vote
0
answers
143
views
Keeping ids and attributes of source features when creating QgsGraph?
I followed the example in QGIS documentation for Network Analysis library to create a graph from a vector layer. When building the graph, the features of the line layer are added as arcs (edges) to ...
- 11
1
vote
1
answer
2k
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QGIS 3 - shortest path routing for multiple pairs of origins and destinations over a road network [closed]
I'm trying to map routes from an O-D survey with about 450,000 individual trips with different start and end points defined by lat, long. I want to estimate total VMT for the area by extrapolating ...
4
votes
1
answer
680
views
Dijkstra/Finding shortest path gives back a tree with only -1 in it
So I'm trying to implement a routing algorithm in my QGIS 3 plugin that I'm writing using Python.
I think I could resolve all the problems concerning the break between QGIS 2 and 3, but my resulting ...
- 109
3
votes
1
answer
3k
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Seeking Vehicle Routing Problem and Location-Allocation Tool in QGIS?
I was wondering if there was a tool in QGIS that is similar to ArcGIS Network Analyst's Vehicle Routing Problem and Location-Allocation tools?
I could not find any info about this in the internet.
1
vote
1
answer
559
views
Distance vs cost in QGIS network analysis
I'd like to calculate shortest route and distance in QGIS 3.2. In the past I have used the v.net.iso, v.net.distance and v.net.path tools. However, I've noticed that there is no distance parameter ...
- 355
3
votes
0
answers
357
views
K-shortest path between two points in QGIS
I am new to QGIS. I have a road network layer in QGIS. I can compute the shortest path between the two points over the road network layer via the Network Analysis toolbox in QGIS.
I am interested in ...
- 31
1
vote
0
answers
922
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Shortest route batch calculation in QGIS 3.2.2 with v.net.path GRASS GUI
I have three shapefiles: road network, postcodes and destinations. I`d like to calculate the shortest route between the postcodes and destinations (multiple points in each layer)
Could anyone ...
- 355
0
votes
1
answer
331
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Line network integration analysis in QGIS
I want to analyse how integrated a line (e.g. road, stream) is within a network.
I want to perform the "integration" type of analysis identified by Javadi (not the connectivity or choice analysis) i.e....
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3
votes
0
answers
130
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Improve performance of QgsVectorLayerDirector.makeGraph() in PyQGIS 3
Porting a plugin that makes excessive use of PyQGIS networking capabilities I had to realize, that building the graph (makeGraph() method of class QgsVectorLayerDirector) in PyQGIS 3 (https://qgis.org/...
- 14.9k
3
votes
0
answers
91
views
Use vector layer attributes as edge properties of a QgsGraphArc with PyQGIS
With PyQGIS 2.18 I created a QgsGraph as describe in the PyQGIS developer cookbook, Release 2.18, ch. 21.2, pp. 95-97. In the cookbook it says
"Vector layer attributes and length of an edge can be ...
- 14.9k
3
votes
1
answer
737
views
Turning QGIS Network Analysis' service area point results into polygons or paths?
After using the Service area tool in QGS 3.0.1, I'm left with a point layer with each feature representing the furthest one can reach on the network given the parameters (max minutes or meters). How ...
- 369
3
votes
1
answer
309
views
QGIS network analysis, points on graph cannot be reached
Using QGIS 2.18.14, I try something around with qgis.networkanalysis module as described here: https://docs.qgis.org/2.18/en/docs/pyqgis_developer_cookbook/network_analysis.html
director = ...
- 14.9k
2
votes
1
answer
653
views
How can I insert the result of the dijkstra algorithm as a feature in a table with PyQGIS?
I ask for your help with the PyQGIS API.
Being a new user of GIS I would like to carry out an operation.
It is for me to look for the shortest path in a graph using the DIJKSTRA algorithm.
The code ...
- 165
2
votes
1
answer
1k
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Unable to open topology file for vector map, grass 7, v.net
I am introducing myself to Qgis using the FOSS4Glabs :
https://github.com/FOSS4GAcademy/GST102FOSS4GLabs/tree/master/Module%206%20Lab/QGIS%202.2
I am facing a problem during the module 6 Lab of ...
12
votes
2
answers
2k
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Computing areas of influence using QGIS
I am trying to create a polygon layer showing polygons that correspond to a closest store.
For a set of 30 store locations, the result should be a polygon layer with 30 features, one for each store. ...
- 822
3
votes
2
answers
1k
views
Fixed distance between two contours in QGIS
Is there a possibility in QGIS 2.14.1 Essen, when you select a contour line and give a fixed length of line, this line connects automatically to the next contour lines?
I have two other questions on ...
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