Vizumap

An R package for visualizing uncertainty in spatial data.

R build status

There is a Vizumap pkgdown site with a vignette.

A Vizumap paper is available in the Journal of Open Source Software (JOSS). If you use Vizumap, please cite this paper.

Installation

You can install Vizumap using the command below.

remotes::install_github(repo = "lydialucchesi/Vizumap", build_vignettes = TRUE, force = TRUE)

About the package

Approaches for visualising uncertainty in spatial data are presented in this package. These include the three approaches developed in Lucchesi and Wikle (2017) and a fourth approach presented in Kuhnert et al. (2018). The package is outlined in Lucchesi et al. (2021).

Bivariate map

In these bivariate choropleth maps, two colour schemes, one representing the estimates and another representing the margins of error, are blended so that an estimate and its error can be conveyed on a map using a single colour.

Pixel map

In this approach, each map region is pixelated. Pixels are filled with colours representing values within an estimate’s margin of error. Regions that appear as a solid colour reflect smaller margins of error, while more pixelated regions indicate greater uncertainty. These maps can be animated to provide a novel uncertainty visualisation experience.

Glyph map

In this method, glyphs located at region centroids are rotated to represent uncertainty. The colour filling each glyph corresponds to the estimate.

Exceedance probability map

The final map-based exploration is through exceedance probabilities, which are visualised on a map to highlight regions that exhibit varying levels of departure from a threshold of concern or target.

Examples

A vignette is available and contains examples for each map type.

vignette("Vizumap")

Contribute

To contribute to Vizumap, please follow these guidelines.

Please note that the Vizumap project is released with a Contributor Code of Conduct. By contributing to this project, you agree to abide by its terms.

License

Vizumap version 1.2.0 is licensed under GPLv3.

Citation

Lucchesi et al., (2021). Vizumap: an R package for visualising uncertainty in spatial data. Journal of Open Source Software, 6(59), 2409, https://doi.org/10.21105/joss.02409

@article{lucchesi2021vizumap,
  title={Vizumap: an R package for visualising uncertainty in spatial data},
  author={Lucchesi, Lydia R and Kuhnert, Petra M and Wikle, Christopher K},
  journal={Journal of Open Source Software},
  volume={6},
  number={59},
  pages={2409},
  year={2021}
}

History of Vizumap

Vizumap began as a visualisation project at the University of Missouri in 2016. Chris Wikle, professor of statistics, posed an interesting research question to Lydia Lucchesi, a student curious about data visualisation and R.

How do you include uncertainty on a map displaying areal data estimates?

Over the course of a year, they put together three methods for visualising uncertainty in spatial statistics: the bivariate choropleth map, the pixel map, and the glyph map. By mid-2017, there were maps, and there was a lot of R code, but there was not a tool that others could use to easily make these types of maps, too. That’s when statistician Petra Kuhnert recommended developing an R package. Over the course of a month, Petra and Lydia developed Vizumap (originally named VizU) at CSIRO Data61 in Canberra, Australia. Since then, the package has been expanded to include exceedance probability maps, an uncertainty visualisation method developed by Petra while working on a Great Barrier Reef (GBR) project.

Vizumap has been used to visualise the uncertainty of American Community Survey estimates, the prediction errors of sediment estimates in a GBR catchment, and most recently the uncertainty of estimated locust densities in Australia. We would like to assemble a Vizumap gallery that showcases different applications of the package’s mapping methods. If you use Vizumap to visualise uncertainty, please feel free to send the map our way. We would like to see it!

References

Kuhnert, P.M., Pagendam, D.E., Bartley, R., Gladish, D.W., Lewis, S.E. and Bainbridge, Z.T. (2018) Making management decisions in face of uncertainty: a case study using the Burdekin catchment in the Great Barrier Reef, Marine and Freshwater Research, 69, 1187-1200, https://doi.org/10.1071/MF17237.

Lucchesi, L.R. and Wikle C.K. (2017) Visualizing uncertainty in areal data with bivariate choropleth maps, map pixelation and glyph rotation, Stat, https://doi.org/10.1002/sta4.150.

Lucchesi, L.R., Kuhnert, P.M. and Wikle, C.K. (2021) Vizumap: an R package for visualising uncertainty in spatial data, Journal of Open Source Software, https://doi.org/10.21105/joss.02409.