ggplot2

Access Open Street Map features programmatically with osmdata package in R

Masumbuko Semba
OpenStreetMaps is a great source of spatial data. Most common programming languages have packages for downloading data from OSM. In this tutorial we are going to see how to download hosptial features data using R’s osmdata (Padgham et al. 2017) package and plot it using ggplot (Wickham 2016), and interactively using tmap (Tennekes 2018). This requires some knowledge of spatial data structures.

CHIRPS precipitation data made easier access in R with wior package

Masumbuko Semba
The Climate Hazards Group InfraRed Precipitation with Station data (CHIRPS) is a quasi-global rainfall data set. As its title suggests it combines data from real-time observing meteorological stations with infra-red satellite data to estimate precipitation. CHIRPS incorporates 0.05° resolution satellite imagery with in-situ station data to create gridded rainfall time series for trend analysis and seasonal drought monitoring. The global dataset covers the area from \(40^\circ\)N to \(4^\circ\)S and from \(20^\circ\)W to \(50^\circ\)E with a spatial resolution of 0.

The Lake Victoria bathymetry

Masumbuko Semba
I was looking for bathymetry dataset for Lake Victoria online and I came across this link. It stores several products of the bathymetry data of the Lake Victoria. Among them products is the gridded TIFF file. This dataset was created by a team from Harvard University in 2017 (Hamilton et al. 2016). They used over 4.2 million points collected over 100-years of surveys. The point data was obtained from an Admiral Bathymetry map and points collected in the field.

Plotting Heatmaps in R with ggplot2 and metR package

Masumbuko Semba
Heatmaps are powerful data visualization tools broadly widely used with meteorologic and oceanographic data. Heatmaps are excellent at tracking signals that move, like ocean current. These diagrams can be used for many more types of atmospheric features. The concept is to represent a matrix of values as colors where usually is organized by a gradient. This post explains how to create a heatmap of ocean current in R using the geom_tile(), geom_contour_filled from ggplot2 (Wickham 2016) and geom_contour_fill from metR package (Campitelli 2019).