pgrouting - Mixedbredie's Ghosts

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pgrouting

A collection of 19 posts

Voronoi isochrones

Voronoi isochrones

How can we visualise our driving distance dataset another way? Can we create something like this which is using Voronoi polygons: Palvealueanalyysi avoimella lähdekoodia #Hämeenlinna #PostGIS #pgRouting #sote #OSGeofi pic.twitter.com/ssyCD0vOxN — Pekka Sarkola (@posiki) May 23, 2017 Well, yes we can. And PostGIS gives us the tools

Processing thousands of journeys: a pgRouting function

Processing thousands of journeys: a pgRouting function

I have a dataset of pupils and the schools they attend. For each pupil I have a source XY coordinate and a target XY coordinate. I have a table of schools where the school name matches the name in the pupil table. I also have a full featured road network

Batch driving distance - a pgRouting function

Batch driving distance - a pgRouting function

A function to batch process driving distance results for a set of input points, in this case, schools. The function creates a table to hold the results (dropping it if it exists) and then selects each school from the your_schools table and calculates the driving distance numbers. For each

Driving Distance Animations with pgRouting - a how to

Driving Distance Animations with pgRouting - a how to

Checklist QGIS with the Time Manager plugin installed. a PostgreSQL database with PostGIS and pgRouting extensions installed. access to said database through psql or pgAdmin3/4 A quick and dirty workflow to create some animations using a road network and some driving distance calculations. I won't go through the process

FOSS4G UK 2016

This is my talk on pgRouting from FOSS4G UK 2016. Pgrouting_foss4guk_ross_mcdonald from Ross McDonald My workshop notes and data are available here. The workshop was designed around using the OSGeo Live DVD so that everyone could work in a controlled environment. If you've got QGIS and PostgreSQL

Building Highways for pgRouting

A copy-and-paste post to help you build the new OS Highways for pgRouting. It is still a work in progress so things may change and break. Requires PostgreSQL with PostGIS and pgRouting and a licensed copy of Safe Software's FME Desktop. 1. Load the data If you have Safe Software’

pgRouting webinar with OS

I recorded a webinar with the Ordnance Survey about the different ways we've been using pgRouting with OS datasets. If you've got 30 minutes spare you can watch it or just read my other blog posts about pgRouting.

All-in-one function to create isochrones

All-in-one function to create isochrones

Well, almost all-in-one. The function currently requires some prep work on the input points before being able to generate the isochrones (alphashapes). The function takes as its arguments the point input table you want the isochrones for and the time in seconds. CREATE OR REPLACE FUNCTION public.make_isochronesX(v_

pgRouting alphashapes - batched

pgRouting alphashapes - batched

A while back I looked at generating alphashapes using pgRouting and displaying in QGIS. It was a pretty convoluted hack though and my SQL skills need some honing. After seeing a post by smathermather that generated isochrones using PostgreSQL functions and the pgRouting algorithms I thought there must be a

pgRouting alphashapes

pgRouting alphashapes

The pgRouting Layer plugin in QGIS gives you access to all the complex routing algorithms in pgRouting through a nice user interface. Once you have solved your route you can export your results saving them for Ron*. But you can't export the results of the driving distance and alpha shapes

The QGIS Road Graph plugin

The QGIS Road Graph plugin

QGIS offers a plugin that will solve a shortest path problem across any vector polyline layer in any format - the Road Graph plugin. The advantage of using this plugin over pgRouting is that you don't need to do anything special to your polyline layer to route across it. As

Improving pgRouting Performance

Improving pgRouting Performance

The Network I've loaded up the new Open Roads network dataset from Ordnance Survey into PostGIS and got it working with pgRouting. I can route successfully from A to B across the network. The problem is that it is so slow. There are 3.18 million road links and 2.

pgRouting and OS Open Roads

ordnance survey

pgRouting and OS Open Roads

Get the data you need from OS: http://www.ordnancesurvey.co.uk/business-and-government/products/os-open-roads.html Load the data into PostGIS using QGIS or pgAdmin or ogr2ogr - your choice. This takes some time to process as there are a large number links making up the network: 3.6 million

pgRouting TRSP in OpenLayers3

pgRouting TRSP in OpenLayers3

I've managed, after some hacking, to write a wrapper to the pgr_trsp function in pgRouting that allows me to use the Turn Restricted Shortest Path to route between two points on the map. It is in the same structure as the Dijkstra Shortest Path wrapper with just a few

pgRouting in OpenLayers3 with reverse costs

The previous post looked at implementing the basic pgRouting workshop OpenLayers3 examples in EPSG:27700. This post adds reverse costs to the mix to take advantage of the road routing information (RRI) supplied with Ordnance Survey's ITN dataset. The changes to the two functions I created are minor - I

pgRouting in OpenLayers3

pgRouting in OpenLayers3

This collection of notes covers my foray into using pgRouting in OpenLayers3 in EPSG:27700, or British National Grid, rather than the usual Google or Spherical Web Mercator projections. This part looks at simply tweaking the tutorial to work in EPSG:27700. The pgRouting workshop (http://workshop.pgrouting.org/) includes

Using pgRouting with OS Meridian2

Using pgRouting with OS Meridian2

A quick guide to building a pgRouting network from Ordnance Survey's Meridian2 dataset. It assumes you have a working PostgreSQL/PostGIS database. The most current information will be on Github: https://github.com/mixedbredie/meridian2-for-pgrouting Get the data Download the Meridian2 shapefiles for the UK from https://www.ordnancesurvey.co.

Using pgRouting with OS Strategi

Using pgRouting with OS Strategi

A quick guide to building a pgRouting network with Ordnance Survey's Strategi dataset. It assumes you have a working PostgreSQL/PostGIS database. The latest information will be on Github: https://github.com/mixedbredie/strategi-for-pgrouting Get the data I downloaded the shapefiles for UK coverage from the Ordnance Survey: https://www.

Building ITN for pgRouting

Building ITN for pgRouting

This document and repository explains how to load Ordnance Survey ITN GML into a PostGIS database with Loader and then build a network suitable for use with pgRouting. The network will have one way streets, no entry and no turn restrictions, mandatory turns and grade separations for over- and underpasses.