Summary: If appending to a PostGIS table with GDAL/OGR is taking a long time, try setting the PG_USE_COPY config option to YES (eg. adding –config PG_USE_COPY YES to your command line). This should speed it up, but beware that if there are concurrent writes to your table at the same time as OGR is accessing […]
I use GeoPandas for a lot of my vector GIS data manipulation in Python. I had a situation the other day where I ended up with duplicates of some geometries in my GeoDataFrame, and I wanted to remove them. The simple way to do this is to use the underlying pandas method drop_duplicates on the […]
Summary: The QGIS Reloader plugin will give you a new QGIS command to reload a layer, very useful when you’re updating a layer in another program and want to refresh QGIS’s view of it. I use QGIS for almost all of my interactive GIS needs. Often I’ll be writing some code in Python that creates […]
I’m giving two talks in the next two weeks, and wanted to publicise them here in case anyone local-ish wants to come. Oxford Cafe Scientifique I’ve spoken at various Cafe Scientifique meet-ups before, and now it’s the turn of the Oxford one. I’ll be giving my talk about the whole range of satellite imaging – […]
Just a quick one this time… GeoParquet is a cool new-ish format for geospatial data. I’ve tried to use it a couple of times, but always run into issues with my GDAL/OGR install not supporting it. Each time this has led to me giving up, as I couldn’t be bothered to install GDAL from somewhere […]
A fun analysis I did a while back was using the Google Maps API to look at travel times between certain locations over time. I originally got interested in this because I found that travelling from my house to the university (yes, that’s how long ago this started…) seemed to either take a very short […]
Following on from my last post on plotting choropleth maps with the leaflet-choropleth library, I’m now going to talk about a small addition I’ve made to the library. Leaflet-choropleth has built-in functionality to automatically categorise your data: you tell it how many categories you’d like and it splits it up. However, once I’d set up […]
Some work I’ve been doing recently has involved putting together a webmap using the Leaflet library. I’ve been very impressed with how Leaflet works, and the range of plugins available for it. leaflet-choropleth is an extension for Leaflet that allows easy generation of choropleth maps in Leaflet. The docs for this module are pretty good, […]
I’ve been doing a bit of freelancing ‘on the side’ for a while – but now I’ve made it official: I am available for freelance work. Please look at my new website or contact me if you’re interested in what I can do for you, or carry on reading for more details. Since I stopped […]
Just a quick reminder that you’ve only got until next Tuesday to bid for a day’s work from me – so get bidding here. The full details and rules are available in my previous post, but basically I’ll do a day’s work for the highest bidder in this auction – working on coding, data science, […]