Posts – GeospatialStuff

Note: some posts show code that has been superseded. Code ran as written at last modified dates.

What three letters

Word games all the way to the ends of the earth

geospatial

r

tutorial

networks

ggplot

life

Maps of all the possible air routes where the origin and destination airport IATA codes would differ by only one letter, and of the ones that actually do. Also, grobs.

David O’Sullivan

A population based binary space partition

Of course there’s a point, I’m just not sure what

geospatial

r

tutorial

aotearoa

population

cartography

A process for building a hierarchical partition of a gridded population dataset

David O’Sullivan

How to cut a cake into four equal slices

If the cake is a country made of people

geospatial

r

tutorial

aotearoa

This ~~journey into the heart of darkness~~ post was inspired by a LinkedIn post from Alasdair Rae linking to a map he made cutting the UK into four equal population slices. The…

David O’Sullivan

North-south or east-west islands?

And why both are wrong

geospatial

r

tutorial

stuff

aotearoa

Rather obviously, the proper names for Aotearoa New Zealand’s two largest islands are Te Ika-a-Maui and Te Waipounamu. It’s not just that those are the names given by the…

David O’Sullivan

Look ma! (Almost) no javascript!

I gave a talk at the local python meetup

geospatial

python

maps

tiling

cartography

weaving

visualization

Last week I gave talk about how I made a web app for our tiled and woven maps work¹ to the Wellington Python meetup held at the Sharesies office on the third Thursday of…

David O’Sullivan

Nine XKCD bad map projections: ranked!

Also: reverse-engineered

geospatial

r

tutorial

stuff

cartography

xkcd

Warning: sensitive souls who care about geodetic accuracy should probably stop reading now. Liberal use of affine transformation of geometries throughout. You have been…

David O’Sullivan

Mostly tiles, but also glyphs

And tiles as glyphs

python

cartography

visualization

tiling

aotearoa

Note: You can take a closer look at any of the maps in this post simply by clicking on them.

David O’Sullivan

Imagine setting up a Jupyter hub

It’s easy if you try

python

training

aotearoa

I’ve worked with :Jupyter notebooks for many years. Almost—but not quite!—since their inception.

David O’Sullivan

MapWeaver: tiled and woven multivariate maps without code

maps

tmap

tiling

weaving

python

How can I make this better? And: is this anything?!

David O’Sullivan

Marimo notebooks

python

tutorial

Reactive notebooks in python!

David O’Sullivan

Into the (LiDAR) void

aotearoa

maps

tmap

geospatial

R

tutorial

life

Or: who’s afraid of the Tararuas?

David O’Sullivan

Random points on the globe revisited

geospatial

R

tutorial

life

Of Christmas gifts and rabbit holes

David O’Sullivan

A welcome (re)emergence of systems thinking

complexity

aotearoa

conferences

systems

And it’s not before time!

David O’Sullivan

ALGIM 2024

local government

geospatial

aotearoa

conferences

On geospatial in local government

David O’Sullivan

tmap vs. ggplot2 for mapping

geospatial

R

qgis

tutorial

tmap

ggplot

I think I prefer…

David O’Sullivan

The joy of DuckDB

geospatial

duckdb

R

tutorial

Insert duck-related joke here

David O’Sullivan

In praise of GeoPackages

geospatial

R

qgis

tutorial

Shapefiles… who needs ’em?

David O’Sullivan

Giscience 2025

conferences

geospatial

aotearoa

Call for papers

David O’Sullivan

GeoCart’2024

cartography

geospatial

aotearoa

conferences

time-space

Reflections on the meeting

David O’Sullivan

Useful utilities for NetLogo

netlogo

simulation

For when you are missing R/python

David O’Sullivan

The model zoo

netlogo

books

simulation

Keeping up with NetLogo

David O’Sullivan

Experiments with R interpolators

R

geospatial

tutorial

Messing around with interpolating via a triangulation to apply coordinate transformations

David O’Sullivan

Spiral origami

javascript

origami

stuff

Things to make and do

David O’Sullivan

OK COVID, you win

visualization

covid

R

maps

The end of the line

David O’Sullivan

Low level handling of sf objects

R

geospatial

Goddamnit, floating point!

David O’Sullivan

Locations of interest in 2021 delta outbreak

maps

visualization

covid

When everything went pear-shaped

David O’Sullivan

Inverse distance weighted (IDW) interpolation using spatstat

R

geospatial

tutorial

So many packages so little time

David O’Sullivan

Kernel density estimation in R spatial

R

geospatial

tutorial

Here’s one way to do kernel density estimation in R spatial

David O’Sullivan

Uniform random points on the globe

R

geospatial

tutorial

The earth’s a sphere: who knew?

David O’Sullivan

Mapping the Dulux colours

R

geospatial

stuff

maps

aotearoa

The ultimate in categorical mapping

David O’Sullivan

Affine transformations of sf objects

R

geospatial

tutorial

Manipulating simple features in sf is sorta simple, sorta not…

David O’Sullivan

What three chords

javascript

geospatial

stuff

Seriously, WTC?!

David O’Sullivan