Sharing our passions
make_point( "auxiliary_storage_labeling_positionx" , "auxiliary_storage_labeling_positiony" )),
make_point( "auxiliary_storage_labeling_positionx" , "auxiliary_storage_labeling_positiony" )
One of the most brilliant but little-known features of QGIS is the ability to trigger layer refreshes and events in response to notifications from PostgreSQL. This was developed by the wizards from Oslandia and is easily added to any existing table in your PostgreSQL database - including PostGIS tables. This feature was added in version 3.0 (see https://qgis.org/en/site/forusers/visualchangelog30/#feature-trigger-layer-refresh-or-layer-actions-from-postgresql-notify-signal). Take for example this simple table:
Thanks to the great work of Grant Slater and the OpenStreetmap team, there are freely available XYZ tilesets for South Africa and Namibia 1:50 000 series toposheets which can easily be added to QGIS. Here is the general procedure to add a layer:
It’s been another awesome year for our Team. We have come a long way since establishing Kartoza in 2014, building many different software products, making friends and working with existing and new clients. Forming a company around an open source friendly business model presents many challenges but is also extremely rewarding. Here is our 2018 year end review that we would like to share with you!
This is the second in a three part series on the behind-the-scenes GIS work that can go into planning a complex event, in this case the Cape Town Marathon.
This is part 1 of a 3-part series.
GIS practitioners and developers have long been interested in versioning spatial data. Luckily the folk at LocationTech have enabled us to do so through the provision of GeoGig (formerly geogit). Moreover, Geogig can interact with GeoServer seamlessly. At Kartoza we use Docker for orchestration of our services and as such it will form the backbone of this article.
Another doc about SSL? Maybe... We are writing this to explain our trial and error on setup SSL on the servers. You might have read somewhere about setting up SSL (so have we, and it's painful).
Our blog is based on hands-on experience and hopefully you can learn something from it.
I preface this article by saying that what I am showing here is probably not best practice and you should test to see if it works reliably for you before taking this route. I should also mention that this is a hacky approach because it breaks our ‘never log on to a server’ rule, so it is not a long-term solution - it is a short-term hack until Hetzner adds a cloud storage offering to their cloud platform.
Well, QGIS 3 has been out for a couple of weeks now with lots of new functionality. While you are still feeling your way around all the new features I thought I could highlight some of the improvements to the browser panel that will make you fall further in love with QGIS.
As a leading Open Source GIS company, Kartoza aims to introduce people and organisations to the world of Open Source GIS in South Africa. The majority of educational institutions in South Africa still teach students GIS and Remote Sensing using proprietary software. During the last few years, there has been a steady increase in institutions migrating to using Open Source GIS systems.
Kartoza is always on the lookout for young and talented students to enroll them in our vacation work or internship program with a possibility of employment. The following story is the experience from our most recent intern, Natalia Dambe, a Master's Student at the University of Cape Town. In her words:
Kartoza recently published the CoGo Plugin (aka Parcel Plugin) in the QGIS plugin repository. This plugin expands the group of plugins designed to manage SDI (Spatial Data Infrastructure). CoGo ('coordinate geometry') refers to its ability to handle both types of coordinates used in land surveying, namely cartesian coordinates (x,y; long/lat) and polar coordinates (bearing and distance).
I have been playing around with roads layers and wanted to change the line directions for some of my features. I looked around for solutions to do this in QGIS and saw that I could use the swap vector direction plugin in QGIS or ST_reverse in PostgreSQL. But I wanted to find a non destructive way to do this as I did not want to alter my data. I decided to try the geometry generator in QGIS.
If you are using QGIS 3 master builds on MacOS and encounter issues with the display of processing dialog layouts like this:
If you need to create a reference grid like this for your map, here's a simple method.
Four of the Kartoza team (Tim, Etienne, Ismail and Rizky) attended the GeoNode Summit in Rome held in November 2016. The World Food Programme provided the venue for the event and our attendance was funded by the WorldBank/GFDRR. The event was a really great opportunity to interact with the GeoNode community. We used the opportunity to learn about the upcoming plans for GeoNode and discuss some of our own plans.
As part of Kartoza's outreach programme, I recently helped the geography department at St Johns College in Johannesburg set up a Tangible Landscape, which to my knowledge is the first in Africa and possibly the first in a secondary school (most are at universities). I've been fascinated by these ever since I saw videos of them in action. So, when Samantha Jones and the rest of the St Johns geography department (Bridget Fleming-HOD, Brandon Louw and Keith Arlow), expressed a wish to have one in the department, Sam's husband, Matt, went ahead and built a frame. That was all the motivation I needed. Peter Henning, the IT Manager at St Johns, gathered an old i5 PC with 4GB RAM (running Ubuntu Linux) and some old monitors and a projector and ordered a Microsoft XBox Kinect. While Peter and Matt set up the infrastructure I set up up the software, mainly consisting of the Open Source GRASS GIS and the module that takes the point clouds coming in from the Kinect and converts them to raster digital elevation models (DEMs).
I recently got hold of h5 files (Hierarchical Data Format (HDF)) and I tried to load them into QGIS and they were drawing in the wrong places.This was because they were not georeferenced. I set out to georeference them using GDAL. Since I was dealing with many h5 files I searched for an automated way to georeference them and could not find one complete solution hence I decided to do it myself with the help of Tim Sutton.