Mixedbredie's Ghosts

Merging DEM rasters

Using batch files and GDAL to merge rasters for performance.

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

pgrouting

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

pgrouting

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

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

qgis

TauDEM Toolbox in QGIS

You might want to use the TauDEM Toolbox in QGIS. The QGIS docs give you all the detail on the available algorithms but you need to install and configure the toolbox yourself. You might get error messages about mpiexec not being being found on your system. QGIS installs most of

blender

Blender Landscapes: Skye

Another attempt at Blender landscapes using the Ordnance Survey Terrain50 DTM and Meridian2 datasets. The Meridian2 features are draped over the DTM which is vertically exaggerated by 150%. Water features and a sea layer are used to create an image texture. This is used in a UVmap to create the

blender

Blender Landscapes

Inspired by an image created by Owen Powell I thought I would have a look at Blender again and see what I could get it to do with elevation and other mapping datasets. Here are some first attempts getting to grips with lighting and UV maps and materials. Auchmithie sunrise

DEM

Texture shading your hillshade

These guys do amazing things creating maps - John M. Nelson, Stephen "Mapsmith", Craig Taylor, Daniel Huffman - and their maps, visualisations and images are inspiring. A tweet by Terry Stigers pointed me at the work of Leland Brown and his texture shading algorithms. I do like a

qgis

QGIS Map Tools at BCS SOC

I recently presented at the BCS SOC annual conference in Cheltenham on the cartographic map tools available in QGIS Essen 2.14 and Nødebo 2.16. BCS\_SOC\_2016\_rossmcdonald\_qgis_maptools Props to Nyall Dawson and Nathan Woodrow for the fantastic new features they've added and the rest of

qgis

Hexperiments in QGIS

After seeing the post by John Nelson on hex binning using ArcGIS I thought I better try it in QGIS as the effect is pretty neat. Open the Processing toolbox and find the QGIS geoalgorithm > Vector Creation Tools > Create Grid Select your grid type: hexagon I created grid

pgrouting

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

pgrouting

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’

data

Merging CSV files

Let's say you want to merge a whole directory of CSV files into one large file to make data management easier. For example, the Ordnance Survey Code-Point Open dataset comes as multiple nested CSV files (121 of them) in one large zip archive. In addition to merging the files into

pgrouting

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.

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_

pgrouting

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

dataviz

Council Tax Data Viz

A simple data visualisation of all properties within development boundaries coloured by council tax band. Multiply blended colours to give an indication of property density which is particularly noticeable in the larger burghs - Arbroath, Brechin, Carnoustie, Kirriemuir, Forfar, Monifieth and Montrose. Created in QGIS 2.14 Essen using blend

qgis

Uninstalling QGIS with SCCM

To make IT sysadmins' lives easier at work (actually, to make my life easier) we use Microsoft's System Centre Configuration Manager (SCCM) to roll out applications to users. We can push out QGIS to machines and the software takes care of 32- or 64-bit architectures and installs the version we

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

gis

Geeking out on a GIS

A couple of months ago Paul Wilson asked a question on KnowledgeHub about the best way to organise data in a GIS. Well, that got the GIS folk out of their data loading torpor and provided some interesting discussion. It highlighted the many different approaches but all seemed to agree

ghost

Getting Varnish, SSL and logging to work with Ghost

I have a complex set up. Varnish in front of Apache serving up cached content on port 80. Requests for secure (HTTPS) pages on port 443 are passed through to the Apache backend which deals with them. And now ghost runs on node.js and port 2368. So I have

gis

QGIS 2.12 Lyon

QGIS 2.12 Lyon has just been released with a ton of new features. I particularly like the new rule based labeling options giving fine grained control. The change log has a very comprehensive list of all the other new features. Download the latest version for your Windows, Mac or

qgis

4th QGIS UK user group in Edinburgh

The next QGIS user group meeting planning and organising is gathering momentum. A free-to-attend full day of open source goodness where you can ask questions, provide answers and tell people about your FOSS4G experiences. Date: 16th November 2015 Time: 9:30 - 16:30 then geobeers Thanks to EDINA for