Posts
Counting points in multipolygon shapefiles for choropleth mapping
Choropleth maps are an excellent way to visualise numbers of observations, but when using point data, calculating the number of points in each polygon can be difficult when using shapefiles. Here we demonstrate how to extract and summarise the number of points in each polygon to create a choropleth map.
Convex and alpha hulls for conservation mapping
Convex hulls and alpha hulls are wonderful alternatives for visualising species distributions when a species has very few existing observations. Here, we will show you how to create these spatial polygons using data from the ALA.
Quantify geographic sampling bias with {sampbias}
Human biases play a large role in the data we collect about species. Here we show a simple method to quantify the bias of roads, cities, rivers and airports on species observations of legless lizards in the Northern Territory
Multiple colour scales in choropleth maps with {ggnewscale}
Using multiple colour scales can be a great way to visually differentiate between geographic categories on a map. Here, we demonstrate this by creating a choropleth map to represent the density of plant records from the ALA across bioregions in Australia, and add multiple colour scales to differentiate marine and terrestrial records
Download plant species data by hexagon to make a 3D hex map
Making plots eye-catching can be useful for science communication. Here, we show how to make 3D plots in R with the `rayshader` package by visualising the number of species identified from ALA observations since 2020
Hex maps for species occurrence data
Hex maps are a neat way to represent spatial information. Here, we show how to draw one using the most common species in the ALA database: the iconic Australian Magpie.
Sunburst plots for taxonomic data
Since version 1.3.1 of `galah`, it has been possible to download taxonomic data using a 'tree' format from the `data.tree` package. Here I'll demonstrate some ideas for plotting these trees using circular diagrams.
Creating a color palette from an image
There are hundreds of color palettes in the R ecosystem, but sometimes we might want to use colors from a specific image. Here I show how to use the `paletter` package to create a color palette for the 2020 Eucalypt of the Year: the Western Australian Gimlet.
