Filippova, D., Lee, J., Olea, A., VanDaniker, M., Wongsuphasawat, K. (May 2008)
Analyzing multivariate geospatial data is a non-trivial task. Geographical location is a variable in itself that might be correlated with other fields in the data. When looking at the variable distribution in a geographical region, users often need to identify areas where the variable is overrepresented. We call such local maxima ”hotspots” and present Fervor: a hotspot explorer. Fervor visualizes hotspots as a continuous heat map and offers a range of tools to investigate relationships within the underlying data. We adopted and expanded the rank-by-feature framework  to quantify the strength of relationships between the different fields describing the data. In this paper, we use Fervor to investigate traffic incident data in the state of Maryland.