postgis - Mixedbredie's Ghosts

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

pgrouting

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_

postgis

ogr2ogr: Oracle to PostGIS

Traditionally^ exporting from Oracle to PostGIS involved an intermediate step Oracle to Shapefile and then Shapefile to PostGIS. But this means that field names longer than 10 characters in Oracle get truncated in the conversion to Shapefile. And using the QGIS or PgAdminIII shp2pgsql gui has no easy way to

postgis

ogr2ogr: PostGIS to PostGIS

I recently^ had to update a live database with updated tables from a staging database and then continue to update on a daily basis. As it is a regular update and the source and destination tables won’t change I generated a text file with a list of layers to

pgrouting

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

pgrouting

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

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

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

pgrouting

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.

pgrouting

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.

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.